Thomas Jefferson wrote the Declaration of Independent, beginning with “We hold these truths to be self evident, that all men are created equal and that they are endowed by their Creator with certain inalienable rights …” This is often quoted as proof that Jefferson, speaking for the Founders, believed that rights were derived from God. That is true, but why were they self evident rather than revealed or inspired by God. Christianity is a religion of revelation, so why would Jefferson claim truths to be self-evident?
The answer is that Jefferson was a Deist, not a Christian. Washington, Adams, Madison, Franklin, Paine were Deists as well. Many, notably Jefferson, spoke well of Christianity and supported Christian ethics. Jefferson considered Christ to be a great philosopher, but not a deity or the son of God.
Not all the Founders were Deists. Many were Christians, and a few, like Ethan Allen, were atheists. Paine sometimes sounds like an atheist, but he was most likely a Deist. Deism still exists, but it was more common in the eighteenth century.
Deists believe that God created the earth and that one day God will return in judgment of mortals. Humans must live in accord with the will of God to be redeemed on the day of judgment. Deists do not believe in the divine inspiration of the Bible. They do not believe that prayers are answered, nor that God speaks directly to man in any way. So how is one to know the will of God in order to obey it?
Man can learn the will of God, the Deists claim, by observing the nature of man. This was referred to as natural law. Madison explained that the U.S. Constitution was derived solely by reference to natural law, without reference to any scripture. He argued, in essence, that using only natural law guaranteed compatibility with all religions, because no divine teaching could be in conflict with the nature of man as observed.
There were more Christians than Deists at the time, but Jefferson and his fellow Deists prevailed in getting Deist concepts accepted in the founding documents. It no doubt helped that there were widely divergent Christian beliefs among the colonies, so that a Christian conception that pleased one denomination would not please the anothers. The Deist argument that all religious beliefs must at heart be reasonable and consistent with natural law was a good compromise.
Some of the early Americans were not so generous. They considered Deism to be heresy at best, and even atheism. Jefferson rewrote the Bible, expunging the stories of miracles. Jefferson and Madison claimed the miracles were added by a monk in the Fourth Century, and they thought is undercut the philosophical teachings of Christ. This did not go over well with some Christians. All of Jefferson’s writings were banned from the public libraries in Philadelphia, a ban that continued through 1840.