You're right & I misspoke; It does matter what he referred to himself as. But, I don't believe he referred to himself as a Christian, and he was hostile to orthodox religion. I should've said "it doesn't matter what he DIDN'T refer to himself as"
Jefferson's original DOI was much more secular, but he had to compromise. Neverthelss, the DOI isn't a governing document; the constitution is. The Constitution makes no mention of God and religion except in exclusionary terms, seperating government and religion.
Nevertheless, we're getting mired in the details and ad-hominim arguments. The point to take home is they all agreed rights are inalienable and they wanted to defend them, and in those rights was the right of religious freedom; to practice what you like without interference, and to never be forced to practice what you don't like. To invoke religion as the justification of promoting religious freedom doesn't make any sense. Let the government do it's secular job secularly.
"No man shall be compelled to frequent or support any religious worship, place, or ministry whatsoever."
-Thomas Jefferson, Virginia Act for Religious Freedom