This is a question sometimes asked by those who never studied what Jefferson himself wrote about his beliefs. If they did they would find this:

“I too have made a wee-little book . . . which I call the ‘Philosophy of Jesus.’ It is made by cutting the texts out of the book (the Bible), and arranging them on the pages of a blank book, in a certain order of time and subject. A more beautiful morsel of ethics I have never seen. It is a document in proof that I am a real Christian, that is to say, a disciple of Jesus, very different from the Platonists, who call me infidel and themselves Christians and preachers of the gospel, while they draw all their characteristic dogmas from what its Author never said or saw. They have compounded from heathen mysteries a system beyond the comprehension of man, of which . . .were He to return on earth would not recognize one feature.” (As quoted in Founding Fathers—Uncommon Heroes, 2003, page 178, by yours truly.)