The notion that Thomas Jefferson was a life-long skeptic is a myth. It can be disproved, for instance, in the fact that in 1777, Jefferson wrote up an agreement for the establishment of a church in Charlottesville, his home. They called a patriotic pastor, an evangelical named Rev. Charles Clay, as the pastor of what became known as the Calvinistical Reformed Church of Charlottesville. It is an ironic name because later in life, Jefferson wrote some scathing indictments against Calvin and Calvinism. Jefferson wrote this 1777 document a year after he wrote the Declaration of Independence, wherein he said our rights come from God.
But in February 1777, Thomas Jefferson himself wrote up this document:
“Subscription to Support a Clergyman in Charlottesville. Whereas by a late act of General assembly freedom of Religious opinion and worship is restored to all, and it is left to the member of each religious society to employ such teachers as they think fit for their own spiritual comfort and instruction, and to maintain the same by their free and voluntary contributions. We the subscribers, professing the most Catholic [i.e., universal] affection for other religious sectaries who happen to differ from us in points of conscience, yet desirous of encouraging and supporting the Calvinistical Reformed Church, and of deriving to ourselves, through the ministry of its teachers, the benefits of Gospel knowledge and religious improvement; and at the same time of supporting those, who, having been at considerable expense in qualifying themselves by regular education for explaining the holy scriptures, have dedicated their time and labour to the service of the said church; and moreover approving highly the political conduct of the Revd. Charles Clay, who, early rejecting the tyrant and tyranny of Britain, proved his religion genuine by its harmony with the liberties of mankind, and, conforming his public prayers to the spirit and the injured rights of his country, ever addressed the God of battles for victory to our arms, while others impiously prayed that our enemies might vanquish and overcome us: do hereby oblige ourselves our heirs executors and administrators to pay to the said Charles Clay of Albemarle his executors or administrators the several sums affixed to our respective names…”
At least at this stage in his life, when he was 33, Thomas Jefferson believed enough in the Gospel of Jesus Christ to help establish a Gospel-preaching church that he helped establish and that he supported as a layman. Why? So that he and the congregation could enjoy “the benefits of Gospel knowledge and religious improvement.” Whatever private, disparaging remarks against orthodox teaching that Jefferson may have made later in life at least prove that if he did lose his faith later in life, his unbelief should not be viewed as characterizing him throughout his life.