“If we could believe that he [Jesus] really countenanced the follies, the falsehoods, and the charlatanism which his biographers [Gospels] father on him, and admit the misconstructions, interpolations, and theorizations of the fathers of the early, and the fanatics of the latter ages, the conclusion would be irresistible by every sound mind that he was an impostor... We find in the writings of his biographers matter of two distinct descriptions. First, a groundwork of vulgar ignorance, of things impossible, of superstitions, fanaticisms and fabrications... That sect [Jews] had presented for the object of their worship, a being of terrific character, cruel, vindictive, capricious and unjust... Jesus had to walk on the perilous confines of reason and religion: and a step to right or left might place him within the gripe of the priests of the superstition, a blood thirsty race, as cruel and remorseless as the being whom they represented as the family God of Abraham, of Isaac and of Jacob, and the local God of Israel. They were constantly laying snares, too, to entangle him in the web of the law... 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.[Letter to William Short, 4 August, 1820]”
“...it is not to be understood that I am with him [Jesus] in all his doctrines. I am a Materialist, he takes the side of spiritualism; he preaches the efficacy of repentance toward forgiveness of sin. I require a counterpoise of good works to redeem it... Among the sayings & discourses imputed to him by his biographers, I find many passages of fine imagination, correct morality, and of the most lovely benevolence: and others again of so much ignorance, so much absurdity, so much untruth, charlatanism, and imposture, as to pronounce it impossible that such contradictions should have proceeded from the same being.[Letter to William Short, 13 April 1820]”
“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 & singularity of opinion... shake off all the fears & 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 of 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 in 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, & 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 & reversed the laws of nature at will, & 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, & the second by exile, or death in fureâ....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... In fine, I repeat, you must lay aside all prejudice on both sides, and neither believe nor reject anything, because any other persons, or description of persons, have rejected or believed it... 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...[Letter to his nephew, Peter Carr, advising him in matters of religion, 1787]”
“he repudiated the writings of the Apostle Paul," whom he considered the (first corrupter of the doctrines of Jesus”
“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...{Letter to John Adams, April 11, 1823}”
“The Christian god can easily be pictured as virtually the same god as the many ancient gods of past civilizations. The Christian god is a three headed monster cruel vengeful and capricious. If one wishes to know more of this raging three headed beast like god one only needs to look at the caliber of people who say they serve him. They are always of two classes fools and hypocrites. ”
“When once we quit the basis of sensation, all is in the wind. 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 Locke, Tracy, and Stewart.{Letter to John Adams, from Monticello, 15 August 1820}”