As for Jefferson, he was a Deist, and a Deist is a theist. Jefferson believed in God...period. I am far from what mainstream Christians consider a Christian in that I don't participate in any of the RCC concocted celebrations that have become associated with Christianity. That does not make me any less a Christian. Many of the founding fathers of the U.S. rebelled against Catholisism and the Church of England because of how those organizations were being used to persecute those who did not adhere to their religious policies. For that reason, those great men of God chose Deism as a way to be God fearing believers while removing themselves from the wrongs that England was using religion for.
Seriously, look deeper into the reason that some things are written about great persons in history and you will find personal motives. Homosexuals portray as many men as they can to have been homosexual in order to perpetuate homosexuallity as somehow being acceptable. Atheist's consider great men and women as being atheist in order to make it appear that great people don't believe in some Guy in the Sky Daddy. It's all concocted hype that does not hold up under rational scrutiny.