I've heard it claimed that Jefferson was a "deist", that he believed in an omnipotent deity that may or may not have been the Christian God. I know there's a body of evidence to support that claim, but you wouldn't know it from visiting the Jefferson Memorial. The following quotes adorn the walls of that memorial; boldface is mine.
We hold these truths to be self-evident: that all men are created equal, that they are endowed by their creator with certain inalienable rights, among these are life, liberty and the pursuit of happiness. That to secure these rights governments are instituted among men...And for the support of this Declaration, with a firm reliance on the protection of divine Providence, we mutually pledge our lives, our fortunes and our sacred honour.
God who gave us life gave us liberty. Can the liberties of a nation be secure when we have removed a conviction that these liberties are the gift of God? Indeed I tremble for my country when I reflect that God is just, that His justice cannot sleep forever...
Almighty God hath created the mind free. All attempts to influence it by temporal punishments or burthens...are a departure from the plan of the Holy Author of our religion...No man shall be compelled to frequent or support any religious worship or ministry or shall otherwise suffer on account of his religious opinions or belief, but all men shall be free to profess and by argument to maintain, their opinions in matters of religion. I know but one code of morality for men whether acting singly or collectively.
I've sworn upon the altar of God Eternal hostility against every form of tyranny over the mind of man.
I don't know the personal religious beliefs of Jefferson the Man, but Jefferson the Icon was a Christian.
There are two other quotes there, one in the rotunda with his statue and one downstairs in the display area. These two speak not to religion, but to government.
I am not an advocate for frequent change in laws and constitutions, but laws and institutions must go hand in hand with the progress of the human mind. As that becomes more developed, more enlightened, as new discoveries are made, new truths discovered and manners and opinions change, with the change of circumstances, institutions must advance also to keep pace with the times. We might as well require a man to wear still the coat which fitted him when a boy as civilized society to remain ever under the regimen of their barbarous ancestors.
The true foundation of republican government is the equal right of every citizen, in his person and property, and in their management.