In the letter to Parker, Jefferson makes clear his vision of an ideal religion.  When considered in context with his other writings, it becomes apparent that Jefferson was interested more in the process of finding a religious philosophy than in a specific rule of religion. 

Let’s look at some other quotes from Thomas Jefferson.  I took these from the Gutenburg project.  I opened the text files and did text searches on “god.”  I skipped the common “god bless you” comments.  I think this gives a quick overview on Jefferson’s thoughts about God.  Notice how near the end Jefferson is more open about his beliefs.  Perhaps, as he approached the end of his life, he became more interested in spiritual matters and less concerned with appearances.  The most interesting  I think is the last letter I included.  It was addressed to the son of a farmer.  

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The God who gave us life, gave us liberty at the same time: the hand of force may destroy, but cannot disjoin them.

–

When, in the course of human events, it becomes necessary for one people to dissolve the political bands which have connected them with another,and to assume among the powers of the earth the separate and equal station to which the laws of nature and of nature’s God entitle them, a decent respect to the opinions of mankind requires that they should declare the causes which impel them to the separation.

We hold these truths to be self evident: that all men are created equal; that they are endowed by their creator with [_inherent and_] (certain) inalienable rights; that among these are life, liberty, and the pursuit of happiness; that to secure these rights, governments are instituted among men, deriving their just powers from the consent of the governed; that whenever any form of government becomes destructive of these ends, it is the right of the people to alter or abolish it, and to institute new government, laying its foundation on such principles, and organizing its powers in such form, as to them shall seem most likely to effect their safety and happiness.

–

For thus I calculate. An insurrection in one of thirteen States, in the course of eleven years that they have subsisted, amounts to one in any particular state, in one hundred and forty-three years, say a century and a half. This would not be near as many as have happened in every other government that has ever existed. So that we shall have the difference between a light and a heavy government as clear gain. I have no fear, but that the result of our experiment will be, that men may be trusted to govern themselves without a master. Could the contrary of this be proved, I should conclude, either that there is no God, or that he is a malevolent being.

 
–

4. Religion, Your reason is now mature enough to examine this object. In the first place, divest yourself of all bias in favor of novelty and singularity of opinion. Indulge them in any other subject rather than that of religion. It is too important, and the consequences of error may be too serious. On the other hand, shake off all the fears and servile prejudices, under which weak minds are servilely crouched.

Fix reason firmly in her seat, and call to her tribunal every fact, every opinion. Question with boldness even the existence of a God; because, if there be one, he must more approve the homage of reason, than that of blindfolded fear. You will naturally examine, first, the religion of your own country.

Read the Bible, then, as you would read Livy or Tacitus. The facts which are within the ordinary course of nature, you will believe on the authority of the writer, as you do those of the same kind in Livy and Tacitus. The testimony of the writer weighs in their favor, in one scale, and their not being against the laws of nature, does not weigh against them. But those facts in the Bible, which contradict the laws of nature, must be examined with more care, and under a variety of faces. Here you must recur to the pretensions of the writer to inspiration from God. Examine upon what evidence his pretensions are founded, and whether that evidence is so strong, as that its falsehood would be more improbable than a change of the laws of nature, in the case he relates. For example, in the book of Joshua we are told the sun stood still several hours. Were we to read that fact in Livy or Tacitus, we should class it with their showers of blood, speaking of statues, beasts, &c. But it is said, that the writer of that book was inspired. Examine, therefore, candidly, what evidence there is of his having been inspired. The pretension is entitled to your inquiry, because millions believe it.

On the other hand, you are astronomer enough to know, how contrary it is to the law of nature, that a body revolving on its axis, as the earth does, should have stopped, should not, by that sudden stoppage, have prostrated animals, trees, buildings, and should after a certain time have resumed its revolution, and that without a second general prostration. Is this arrest of the earth’s motion, or the evidence which affirms it, most within the law of probabilities?

You will next read the New Testament. It is the history of a personage called Jesus. Keep in your eye the opposite pretensions, 1. of those who say he was begotten by God, born of a virgin, suspended, and reversed the laws of nature at will, and ascended bodily into heaven: and, 2. of those who say he was a man, of illegitimate birth, of a benevolent heart, enthusiastic mind, who set out without pretensions to divinity, ended in believing them, and was punished capitally for sedition, by being gibbeted, according to the Roman law, which punished the first commission of that offence by whipping, and the second by exile or death _in furca_. See this law in the Digest, Lib. 48, tit. 19, § 28. 3. and Lipsius, Lib. 2. _De Cruce_, cap. 2. These questions are examined in the books I have mentioned, under the head of Religion, and several others. They will assist you in your inquiries; but keep your reason firmly on the watch in reading them all. Do not be frightened from this inquiry by any fear of its consequences.

If it ends in a belief that there is no God, you will find incitements to virtue in the comfort and pleasantness you feel in its exercise, and the love of others which it will procure you.

If you find reason to believe there is a God, a consciousness that you are acting under his eye, and that he approves you, will be a vast additional incitement: if that there be a future state, the hope of a happy existence in that, increases the appetite to deserve it: if that Jesus was also a God, you will be comforted by a belief of his aid and love.

In fine, I repeat, you must lay aside all prejudice on both sides, and neither believe nor reject any thing, because any other person, or description of persons, have rejected or believed it. Your own reason is the only oracle given you by Heaven, and you are answerable not for the rightness, but uprightness of the decision.

I forgot to observe, when speaking of the New Testament, that you should read all the histories of Christ, as well of those whom a council of ecclesiastics have decided for us to be Pseudo-evangelists, as those they named Evangelists. Because these Pseudo-evangelists pretended to inspiration as much as the others, and you are to judge their pretensions by your own reason, and not by the reason of those ecclesiastics. Most of these are lost. There are some, however, still extant, collected by Fabricius, which I will endeavor to get and send you.

–

I promised you a letter on Christianity, which I have not forgotten. On the contrary, it is because I have reflected on it, that I find much more time necessary for it than I can at present dispose of. I have a view of the subject which ought to displease neither the rational Christian nor Deist, and would reconcile many to a character they have too hastily rejected. I do not know that it would reconcile the _genus irritabile vatum_, who are all in arms against me. Their hostility is on too interesting ground to be softened. The delusion into which the X. Y. Z. plot showed it possible to push the people; the successful experiment made under the prevalence of that delusion on the clause of the constitution, which, while it secured the freedom of the press, covered also the freedom of religion, had given to the clergy a very favorite hope of obtaining an establishment of a particular form of Christianity through the United States; and as every sect believes its own form the true one, every one perhaps hoped for his own, but especially the Episcopalians and Congregationalists. The returning good sense of our country threatens abortion to their hopes, and they believe that any portion of power confided to me, will be exerted in opposition to their schemes. And they believe rightly: for I have sworn, upon the altar of God, eternal hostility against every form of tyranny over the mind of man. But this is all they have to fear from me: and enough too in their opinion. And this is the cause of their printing lying pamphlets against me, forging conversations for me with Mazzei, Bishop Madison, &c. which are absolute falsehoods without a circumstance of truth to rest on; falsehoods, too, of which I acquit Mazzei and Bishop Madison, for they are men of truth.

–

The approbation of my ancient friends is above all things the most grateful to my heart. They know for what objects we relinquished the delights of domestic society, tranquillity, and science, and committed ourselves to the ocean of revolution, to wear out the only life God has given us here, in scenes, the benefits of which will accrue only to those who follow us.

–

We must reduce our volume to the simple evangelists, select, even from them, the very words only of Jesus, paring off the amphiboligisms into which they have been led, by forgetting often, or not understanding, what had fallen from him, by giving their own misconceptions as his dicta, and expressing unintelligibly for others what they had not understood themselves. There will be found remaining the most sublime and benevolent code of morals which has ever been offered to man. I have performed this operation for my own use, by cutting verse by verse out of the printed book, and arranging the matter which is evidently his, and which is as easily distinguishable as diamonds, in a dunghill. The result is an octavo of forty-six pages, of pure and unsophisticated doctrines, such as were professed and acted on by the unlettered Apostles, the Apostolic Fathers, and the Christians, of the first century. Their Platonizing successors, indeed, in after times, in order to legitimate the corruptions which they had incorporated into the doctrines of Jesus, found it necessary to disavow the primitive Christians, who had taken their principles from the mouth of Jesus himself, of his Apostles, and the Fathers cotemporary with them.
…
I think you give a just outline of the theism of the three religions, when you say that the principle of the Hebrew was the fear, of the Gentile the honor, and of the Christian the love of God.

An expression in your letter of September the 14th, that ‘the human understanding is a revelation from its maker,’ gives the best solution that I believe can be given of the question, ‘What did Socrates mean by his Daemon?’ He was too wise to believe, and too honest to pretend, that he had real and familiar converse with a superior and invisible being. He probably considered the suggestions of his conscience, or reason, as revelations, or inspirations from the Supreme mind, bestowed, on important occasions, by a special superintending providence.

I acknowledge all the merit of the hymn of Cleanthes to Jupiter, which you ascribe to it. It is as highly sublime as a chaste and correct imagination can permit itself to go. Yet in the contemplation of a being so superlative, the hyperbolic flights of the Psalmist may often be followed with approbation, even with rapture; and I have no hesitation in giving him the palm over all the hymnists of every language, and of every time. Turn to the 148th psalm in Brady and Tate’s version. Have such conceptions been ever before expressed? Their version of the 15th psalm is more to be esteemed for its pithiness than its poetry. Even Sternhold, the leaden Sternhold, kindles, in a single instance, with the sublimity of his original, and expresses the majesty of God descending on the earth, in terms not unworthy of the subject.

 
–

One of our fan-coloring biographers, who paints small men as very great, inquired of me lately, with real affection too, whether he might consider as authentic, the change in my religion much spoken of in some circles. Now this supposed that they knew what had been my religion before, taking for it the word of their priests, whom I certainly never made the confidants of my creed. My answer was, ‘Say nothing of my religion. It is known to my God and myself alone. Its evidence before the world is to be sought in my life; if that has been honest and dutiful to society, the religion which has regulated it cannot be a bad one.

–

That Jesus did not mean to impose himself on mankind as the Son of God, physically speaking, I have been convinced by the writings of men more learned than myself in that lore. But that he might conscientiously believe himself inspired from above, is very possible. The whole religion of the Jews, inculcated on him from his infancy, was founded in the belief of divine inspiration. The fumes of the most disordered imaginations were recorded in their religious code, as special communications of the Deity; and as it could not but happen that, in the course of ages events would now and then turn up to which some of these vague rhapsodies might be accommodated by the aid of allegories, figures, types, and other tricks upon words, they have not only preserved their credit with the Jews of all subsequent times, but are the foundation of much of the religions of those who have schismatized from them. Elevated by the enthusiasm of a warm and pure heart, conscious of the high strains of an eloquence which had not been taught him, he might readily mistake the coruscations of his own fine genius for inspirations of an higher order. This belief, carried, therefore, no more personal imputation, than the belief of Socrates, that himself was under the care and admonitions of a guardian Daemon. And how many of our wisest men still believe in the reality of these inspirations, while perfectly sane on all other subjects. Excusing, therefore, on these considerations, those passages in the gospels which seem to bear marks of weakness in Jesus, ascribing to him what alone is consistent with the great and pure character of which the same writings furnish proofs, and to their proper authors their own trivialities and imbecilities, I think myself authorized to conclude the purity and distinction of his character, in opposition to the impostures which those authors would fix upon him; and that the postulate of my former letter is no more than is granted in all other historical works.

–

To talk of immaterial existences, is to talk of nothings. To say that the human soul, angels, God, are immaterial, is to say, they are nothings, or that there is no God, no angels, no soul. I cannot reason otherwise: but I believe I am supported in my creed of materialism by the Lockes, the Tracys, and the Stewarts. At what age of the Christian church this heresy of immaterialism, or masked atheism, crept in, I do not exactly know. But a heresy it certainly is. Jesus taught nothing of it. He told us, indeed, that ‘God is a spirit,’ but he has not defined what a spirit is, nor said that it is not matter.

–

TO DOCTOR BENJAMIN WATERHOUSE.

Monticello, June 26, 1822.

Dear Sir,
I have received and read with thankfulness and pleasure your denunciation of the abuses of tobacco and wine. Yet, however sound in its principles, I expect it will be but a sermon to the wind. You will find it is as difficult to inculcate these sanative precepts on the sensualities of the present day, as to convince an Athanasian that there is but one God. I wish success to both attempts, and am happy to learn from you that the latter, at least, is making progress, and the more rapidly in proportion as our Platonizing Christians make more stir and noise about it. The doctrines of Jesus are simple, and tend all to the happiness of man.

1. That there is one only God, and he all perfect.

2. That there is a future state of rewards and punishments.

3. That to love God with all thy heart, and thy neighbor as thyself, is the sum of religion. These are the great points on which he endeavored to reform the religion of the Jews. But compare with these the demoralizing dogmas of Calvin.

1. That there are three Gods.

2. That good works, or the love of our neighbor, are nothing.

3. That faith is everything, and the more incomprehensible the proposition, the more merit in its faith.

4. That reason in religion is of unlawful use.

5. That God, from the beginning, elected certain individuals to be saved, and certain others to be damned; and that no crimes of the former can damn them; no virtues of the latter, save.

Now, which of these is the true and charitable Christian? He who believes and acts on the simple doctrines of Jesus; or the impious dogmatists, as Athanasius and Calvin? Verily I say these are the false shepherds foretold as to enter not by the door into the sheepfold, but to climb up some other way. They are mere usurpers of the Christian name, teaching a counter-religion made up of the deliria of crazy imaginations, as foreign from Christianity as is that of Mahomet. Their blasphemies have driven thinking men into infidelity, who have too hastily rejected the supposed author himself, with the horrors so falsely imputed to him. Had the doctrines of Jesus been preached always as pure as they came from his lips, the whole civilized world would now have been Christian. I rejoice that in this blessed country of free inquiry and belief, which has surrendered its creed and conscience to neither kings nor priests, the genuine doctrine of one only God is reviving, and I trust that there is not a young man now living in the United States, who will not die an Unitarian.

But much I fear, that when this great truth shall be re-established, its votaries will fall into the fatal error of fabricating formulas of creed and confessions of faith, the engines which so soon destroyed the religion of Jesus, and made of Christendom a mere Aceldama; that they will give up morals for mysteries, and Jesus for Plato. How much wiser are the Quakers, who, agreeing in the fundamental doctrines of the Gospel, schismatize about no mysteries, and, keeping within the pale of common sense, suffer no speculative differences of opinion, any more than of feature, to impair the love of their brethren. Be this the wisdom of Unitarians, this the holy mantle which shall cover within its charitable circumference all who believe in one God, and who love their neighbor! I conclude my sermon with sincere assurances of my friendly esteem and respect.

Th: Jefferson

–

TO JAMES SMITH.

Monticello, December 8, 1822.

Sir,
I have to thank you for your pamphlets on the subject of Unitarianism, and to express my gratification with your efforts for the revival of primitive Christianity in your quarter. No historical fact is better established, than that the doctrine of one God, pure and uncompounded, was that of the early ages of Christianity; and was amoung the efficacious doctrines which gave it triumph over the polytheism of the ancients, sickened with the absurdities of their own theology. Nor was the unity of the Supreme Being ousted from the Christian creed by the force of reason, but by the sword of civil government, wielded at the will of the fanatic Athanasius. The hocus-pocus phantasm of a God like another Cerberus, with one body and three heads, had its birth and growth in the blood of thousands and thousands of martyrs. And a strong proof of the solidity of the primitive faith, is its restoration, as soon as a nation arises which vindicates to itself the freedom of religious opinion, and its external divorce from the civil authority. The pure and simple unity of the Creator of the universe, is now all but ascendant in the eastern States; it is dawning in the west, and advancing towards the south; and I confidently expect that the present generation will see Unitarianism become the general religion of the United States. The eastern presses are giving us many excellent pieces on the subject, and Priestley’s learned writings on it are, or should be, in every hand. In fact, the Athanasian paradox that one is three, and three but one, is so incomprehensible to the human mind, that no candid man can say he has any idea of it, and how can he believe what presents no idea? He who thinks he does, only deceives himself. He proves, also, that man, once surrendering his reason, has no remaining guard against absurdities the most monstrous, and like a ship without rudder, is the sport of every wind. With such persons, gullability, which they call faith, takes the helm from the hand of reason, and the mind becomes a wreck.

I write with freedom, because, while I claim a right to believe in one God, if so my reason tells me, I yield as freely to others that of believing in three. Both religions, I find, make honest men, and that is the only point society has any right to look to. Although this mutual freedom should produce mutual indulgence, yet I wish not to be brought in question before the public on this or any other subject, and I pray you to consider me as writing under that trust. I take no part in controversies, religious or political. At the age of eighty, tranquillity is the greatest good of life, and the strongest of our desires that of dying in the good-will of all mankind. And with the assurances of all my good-will to Unitarian and Trinitarian, to Whig and Tory, accept for yourself that of my entire respect.

Th: Jefferson

–

TO JOHN ADAMS.

Monticello, April 11, 1823.

Dear Sir,
The wishes expressed in your last favor, that I may continue in life and health until I become a Calvinist, at least in his exclamation of, ‘_Mon Dieu! jusqu’a quand?_’ would make me immortal. I can never join Calvin in addressing his God. He was indeed an atheist, which I can never be; or rather his religion was daemonism. If ever man worshipped a false God, he did. The being described in his five points, is not the God whom you and I acknowledge and adore, the Creator and benevolent Governor of the world; but a daemon of malignant spirit. It would be more pardonable to believe in no God at all, than to blaspheme him by the atrocious attributes of Calvin. Indeed, I think that every Christian sect gives a great handle to atheism by their general dogma, that, without a revelation, there would not be sufficient proof of the being of a God. Now one sixth of mankind only are supposed to be Christians: the other five sixths then, who do not believe in the Jewish and Christian revelation, are without a knowledge of the existence of a God! This gives completely a _gain de cause_ to the disciples of Ocellus, Timasus, Spinosa, Diderot, and D’Holbach. The argument which they rest on as triumphant and unanswerable is, that in every hypothesis of cosmogony, you must admit an eternal pre-existence of something; and according to the rule of sound philosophy, you are never to employ two principles to solve a difficulty when one will suffice. They say then, that it is more simple to believe at once in the eternal pre-existence of the world, as it is now going on, and may for ever go on by the principle of reproduction which we see and witness, than to believe in the eternal pre-existence of an ulterior cause, or creator of the world, a being whom we see not and know not, of whose form, substance, and mode, or place of existence, or of action, no sense informs us, no power of the mind enables us to delineate or comprehend. On the contrary, I hold (without appeal to revelation), that when we take a view of the universe, in its parts, general or particular, it is impossible for the human mind not to perceive and feel a conviction of design, consummate skill, and indefinite power in every atom of its composition. The movements of the heavenly bodies, so exactly held in their course by the balance of centrifugal and centripetal forces; the structure of our earth itself, with its distribution of lands, waters, and atmosphere; animal and vegetable bodies, examined in all their minutest particles; insects, mere atoms of life, yet as perfectly organized as man or mammoth; the mineral substances, their generation and uses; it is impossible, I say, for the human mind not to believe, that there is in all this, design, cause, and effect, up to an ultimate cause, a fabricator of all things from matter and motion, their preserver and regulator while permitted to exist in their present forms, and their regenerator into new and other forms. We see, too, evident proofs of the necessity of a superintending power, to maintain the universe in its course and order. Stars, well known, have disappeared, new ones have come into view; comets, in their incalculable courses, may run foul of suns and planets, and require renovation under other laws; certain races of animals are become extinct; and were there no restoring power, all existences might extinguish successively, one by one, until all should be reduced to a shapeless chaos. So irresistible are these evidences of an intelligent and powerful agent, that, of the infinite numbers of men who have existed through all time, they have believed, in the proportion of a million at least to unit, in the hypothesis of an eternal pre-existence of a creator, rather than in that of a self-existent universe. Surely this unanimous sentiment renders this more probable, than that of the few in the other hypothesis. Some early Christians, indeed, have believed in the co-eternal pre-existence of both the creator and the world, without changing their relation of cause and effect. That this was the opinion of St. Thomas, we are informed by Cardinal Toleta, in these words; ‘_Deus ab terno fuit jam omnipotens, si cut cum produxit mundum. Ah aternopotuit producers mundum. Si sol ah czterno esset, lumen ah æterno esset; et si pes, similiter vestigium. At lumen et vestigium effectus sunt efficients solis et pedis; potuit ergo cum causa æterna effectus coaternus esse. Cujus sententia, est S. Thomas, theologorum primus_.’–Cardinal Toleta.

Of the nature of this being we know nothing. Jesus tells us, that ‘God is a spirit’(John iv. 24.), but without defining what a spirit is: [Greek phrase] Down to the third century, we know that it was still deemed material but of a lighter, subtler matter than our gross bodies. So says Origen; _Deus igitur, cui anima similis est, juxta Originem, reapte corporalis est; sed graviorum tantum ratione corporum incorporeus_.’ These are the words of Huet in his commentary on Origen. Origen himself says, [Greek and Latin phrase]
…
But the reformation of these blasphemous attributes, and substitution of those more worthy, pure, and sublime, seems to have been the chief object of Jesus in his discourses to the Jews: and his doctrine of the cosmogony of the world is very clearly laid down in the three first verses of the first chapter of John, in these words: [Greek phrase] Which, truly translated, means, ‘In the beginning God existed, and reason [or mind] was with God, and that mind was God. This was in the beginning with God. All things were created by it, and without it was made not one thing which was made.’ Yet this text, so plainly declaring the doctrine of Jesus, that the world was created by the supreme intelligent being, has been perverted by modern Christians to build up a second person of their tritheism, by a mistranslation of the word _Xoyog_. One of its legitimate meanings, indeed, is ‘a word.’ But in that sense it makes an unmeaning jargon: while the other meaning, ‘reason,’ equally legitimate, explains rationally the eternal pre-existence of God, and his creation of, the world. Knowing how incomprehensible it was that ‘a word,’ the mere action or articulation of the organs of speech could create a world, they undertook to make of this articulation a second pre-existing being, and ascribe to him, and not to God, the creation of the universe. The atheist here plumes himself on the uselessness of such a God, and the simpler hypothesis of a self-existent universe. The truth is, that the greatest enemies to the doctrines of Jesus are those calling themselves the expositors of them, who have perverted them for the structure of a system of fancy absolutely incomprehensible, and without any foundation in his genuine words. And the day will come, when the mystical generation of Jesus, by the Supreme Being as his father, in the womb of a virgin, will be classed with the fable of the generation of Minerva in the brain of Jupiter. But we may hope that the dawn of reason, and freedom of thought, in these United States, will do away all this artificial scaffolding, and restore to us the primitive and genuine doctrines of this the most venerated reformer of human errors.

–

THOMAS JEFFERSON TO THOMAS JEFFERSON SMITH.

This letter will, to you, be as one from the dead. The writer will be in the grave before you can weigh its counsels. Your affectionate and excellent father has requested that I would address to you something which might possibly have a favorable influence on the course of life you have to run, and I too, as a namesake, feel an interest in that course. Few words will be necessary, with good dispositions on your part. Adore God. Reverence and cherish your parents. Love your neighbor as yourself, and your country more than yourself. Be just. Be true. Murmur not at the ways of Providence. So shall the life, into which you have entered, be the portal to one of eternal and ineffable bliss. And if to the dead it is permitted to care for the things of this world, every action of your life will be under my regard. Farewell.

Monticello, February 21, 1825.

_The Portrait of a Good Man, by the most sublime of Poets, for your imitation_.

Lord, who’s the happy man that may to thy blest courts repair;
Not stranger-like to visit them, but to inhabit there?
‘Tis he, whose every thought and deed by rules of virtue moves;
Whose generous tongue disdains to speak the thing his heart
disproves.
Who never did a slander forge, his neighbor’s fame to wound;
Nor hearken to a false report, by malice whispered round.
Who vice, in all its pomp and power, can treat with just neglect;
And piety, though clothed in rags, religiously respect.
Who to his plighted vows and trust has ever firmly stood;
And though he promise to his loss, he makes his promise good.
Whose soul in usury disdains his treasure to employ;
Whom no rewards can ever bribe the guiltless to destroy.
The man, who, by this steady course, has happiness insured,
When earth’s foundations shake, shall stand, by Providence secured.

– 

The extracts I selected are not a conclusive selection, but they are enough to get an overview of Jefferson’s religious beliefs. Jefferson says clearly that he is either a Rational Christian (Unitarian) or Deist. (In Amorian.org I treat Rational Christianity and Unitarianism as forms of Deism, so I will just refer to Jefferson’s belief as a form of Deism.) He addresses religion almost as philosophy. He treats Jesus as a philosopher, and Trinitarian Christians as deluded, although, later in his life he concedes that both Unitarian and Trinitarian Christianity lead to a virtuous life.

Jefferson’s goal in life is to live a good life and to find the kingdom of heaven that is within, or in his own words: “Your own reason is the only oracle given you by Heaven, and you are answerable not for the rightness, but uprightness of the decision.” He argues that you don’t need to be correct, but you do need to act out of desire for virtuous.

As far as reason is concerned, Jefferson equates reason with rationality. Today we tend to create reason with thinking. Reason in modern society tends to mean coming to a consensus as being logically correct. When we say that we lead someone to reason, we mean that we lead them to agree with us, which doesn’t necessarily have anything to do with rational correctness.

He discouraged the creation of a religious system of Deism, because all such systems eventually become corrupt. At the same time he gave a few simple guidelines to live by. “The doctrines of Jesus are simple, and tend all to the happiness of man. 1. That there is one only God, and he all perfect. 2. That there is a future state of rewards and punishments. 3. That to love God with all thy heart, and thy neighbor as thyself, is the sum of religion.” And in his letter to Thomas Jefferson Smith he advises, “Adore God. Reverence and cherish your parents. Love your neighbor as yourself, and your country more than yourself. Be just. Be true. Murmur not at the ways of Providence. So shall the life, into which you have entered, be the portal to one of eternal and ineffable bliss.”

Jefferson argues that divine revelation is not necessary to believe in God. God can be proved by looking at the infinite complexity of the universe. He argues for an eternal pre-existent creator.

Jefferson’s Deism recognizes God as the source of nature. He rejects formal systems and advocates study, belief in virtue as found within, and love as a foundation for living.

The only thing I improvement I make in Jefferson’s Deism in the religious philosophy of Amorianism is that love must be tempered by proper behavior because some of the greatest wrongs that have been done out of love. Proper behavior must be found in rationality, not reason. Reason is the foundation of virtue, but rationality must be reason’s foundation, otherwise reason becomes rationale.

<UPDATE: Feb. 7, 2010>

As a side note, I found this interesting comment from Jefferson about the faith of George Washington in the Gutenburg documents: 

Doctor Rush tells me that he had it from Asa Green,
that when the clergy addressed General Washington on his departure
from the government, it was observed in their consultation, that he had
never, on any occasion, said a word to the public which showed a belief
in the Christian religion, and they thought they should so pen their
address, as to force him at length to declare publicly whether he was a
Christian or not. They did so. However, he observed, the old fox was
too cunning for them. He answered every article of their address
particularly except that, which he passed over without notice. Rush
observes, he never did say a word on the subject in any of his public
papers, except in his valedictory letter to the Governors of the States
when he resigned his commission in the army, wherein he speaks of ‘the
benign influence of the Christian religion.’

I know that Gouverneur Morris, who pretended to be in his secrets and
believed himself to be so, has often told me that General Washington
believed no more of that system than he himself did.

.