The article linked by thealchemist, shows they were Pagans. Jefferson wrote the Jefferson bible in which he removed all references to Jewsus's divinity and made him just a person. This was to remove Christianity's hold over peoples minds. Its the most anti-Christian thing he could have done in that regard.
Washington stood up and addressed the American Congresses over the treaty of Tripoli and stated that America is in no way a nation founded on any Christian principals. The Congress chaplain that had lunch every Friday for the entire duration of Washington's presidency stated when asked on the subject of Washington being a Christian, that Washington was open that he was not Christian. Washington was well know to refuse to take communion at the Church him and his wife attended. Which is a denial of belief in Christ. He only attended Church because his wife wanted him to for social reasons.
Jefferson was also a Luciferian Mason like Washington and Franklin. Franklin was a member of the Hell Fire Club, a Luciferian Masonic group that held occult rituals against Christianity and the Church. Franklin was close friends with and initiated Voltaire, and it was Voltaire who stated that he would personally destroy Christianity.