At best he was a pamphleteer, a very good one who was clearly helpful in inspiring the Patriots during the American Revolution.
But his "Age of Reason" was written much later when he was imprisoned in France. American leaders honored him for his service in his declining years but his religious views were NOT roundly embraced by the Americans as his inspirations to revolt were by the Patriots.
His career turned to journalism while in Philadelphia, and suddenly, Thomas Paine became very important. In 1776, he published Common Sense, a strong defense of American Independence from England. He traveled with the Continental Army and wasn't a success as a soldier, but he produced The Crisis (1776-83), which helped inspire the Army. This pamphlet was so popular that as a percentage of the population, it was read by or read to more people than today watch the Super Bowl.
But, instead of continuing to help the Revolutionary cause, he returned to Europe and pursued other ventures, including working on a smokeless candle and an iron bridge. In 1791-92, he wrote The Rights of Man in response to criticism of the French Revolution. This work caused Paine to be labeled an outlaw in England for his anti-monarchist views. He would have been arrested, but he fled for France to join the National Convention.
By 1793, he was imprisoned in France for not endorsing the execution of Louis XVI. During his imprisonment, he wrote and distributed the first part of what was to become his most famous work at the time, the anti-church text, The Age of Reason (1794-96). He was freed in 1794 (narrowly escaping execution) thanks to the efforts of James Monroe, then U.S. Minister to France. Paine remained in France until 1802 when he returned to America on an invitation from Thomas Jefferson. Paine discovered that his contributions to the American Revolution had been all but eradicated due to his religious views. Derided by the public and abandoned by his friends, he died on June 8, 1809 at the age of 72 in New York City.
Paine’s harshest critics regard him as little more than a polemicist, or a propagandist (in modern parlance). It seems to be true that when Paine turned from unseating kings to unseating bishops, his rhetoric changed accordingly. Paine was wonderfully popular with the American People in 1776 when he wrote Common Sense, and excited no animosity with The Rights of Man in 1792. But his Age of Reason in 1794, which was no more than a vicious attack on the Holy Bible and having nothing to do with either enlightenment or government, turned them against him and the reverse was irrevocable (Adams was furious with him to near sputtering, his reaction mirroring that of the American People). Paine died unforgiven for his betrayal.
What is astonishing is the reaction of the modern enemies of the Judeo-Christian tradition who seem to think that Paine’s 1794 composition of the The Age of Reason could somehow have had an influence on the American revolutionary act of 1776. Incomprehensible.