Francis Lightfoot Lee was an Anglican and a devout Christian.
From: B. J. Lossing, Signers of the Declaration of Independence, George F. Cooledge & Brother: New York (1848) [reprinted in Lives of the Signers of the Declaration of Independence, WallBuilder Press: Aledo, Texas (1995)], pages 194-196:
Francis Lightfoot Lee, a younger brother of Richard Henry Lee, was born in Westmoreland couny, Virginia, on the fourteenth day of October, 1734. He was too young when his father died to be sent abroad to be educated, but was favored with every advantage in the way of learning which the colony afforded. He was placed at an early age under the care of the Reverend Doctor Craig, a Scotch clergyman of eminient piety and learning. His excellent tutor not only educated his head but his heart, and laid the foundation of character, upon which the noble superstructure, which his useful life exhibited, was reared.From: Robert G. Ferris (editor), Signers of the Declaration: Historic Places Commemorating the Signing of the Declaration of Independence, published by the United States Department of the Interior, National Park Service: Washington, D.C. (revised edition 1975), page 90-91:
...Mr. Lee continued in Congress, until 1779, and was the member, for Virginia, of the committee which framed the Articles of Confederation. Early in the spring of 1779, he retired from Congress and returned home, with the intention of withdrawing wholly from public life, to enjoy those sweets of domestic quiet which he so ardently loved. But his fellow citizens were unwilling to dispense with his valuable services, and elected him a member of the Virginia Senate.He, however, remained there but for a brief season, and then bade adieu to public employments. He could never again be induced to leave his domestic pleasures; and he passed the remainder of his days in agricultural pursuits, and the enjoyments to be derived from reading and study, and the cheerful intercourse with friends. Possessed of ample wealth, he used it like a philosopher and a Christian in dispensing its blessings for the benefit of his country and his fellow men.
No less a patriot than his dynamic elder brother Richard Henry [Lee, a fellow signer of the Declaration of Independence] and his gifted younger brothers Arthur and William, Francis Lightfoot Lee preferred the unenventful life of a country squire to the public spotlight and chose to follow rather than lead. Despite his shyness and weakness as a speaker, he exercised extensive political influence, took an active part in the Revolution, and signed both the Declaration and the Articles of Confederation.
...[He was buried] in the Tayloe family graveyard at Mount Airy [the graveyard of his wife's family].