Mr. Jefferson's Deism
Avery Dulles, "The Deist Minimum," First Things, January 2005, pp. 25-30. (Link courtesy of Dymphna.)
In summary, then, Jefferson was a deist because he believed in one God, in divine providence, in the divine moral law, and in rewards and punishments after death, but did not believe in supernatural revelation. He was a Christian deist because he saw Christianity as the highest expression of natural religion and Jesus as an incomparably great moral teacher. He was not an orthodox Christian because he rejected, among other things, the doctrines that Jesus was the promised Messiah and the incarnate Son of God.
Jefferson’s religion is fairly typical of the American form of deism in his day. But a vocal minority of American deists were, like many of the French Encyclopedists, opposed to Christianity. Thomas Paine, the most famous of this group, was often accused of atheism, but he, like Voltaire, believed in God the Creator. Even radical deists like Paine agreed with Jefferson and Franklin that without belief in God and in a future life, morality in society could not be sustained.