Despite his hatred of monarchies, Paine did not want to execute king Louis, because he did not believe in revenge killings. This put him at odds with Robespierre, who imprisoned him and ordered him executed. He survived by mere chance, the guard who marked the prison doors to signal who was to executed accidentally marked on the wrong side of Paine's cell door, thus sparing his life. Thomas Paine literally almost died defending universal liberty.
In his time in captivity, Paine stayed busy. He wrote his opinion on religion and God, entitled The Age of Reason. Paine was a Deist, and he believed that all religions were "human inventions" and "set up to terrify and enslave mankind." In the Age of Reason, Paine attacked Christianity, Judaism, and Islam, but defended God as revealed by nature, God without religion. Paine's stated goal was to throw off the shackles of religion, just like he had thrown off the shackles of kings. Sadly, his work was not received well in America, as people had become more conservative since the revolution. Once Paine managed to return to America, he was targeted as an evil antichrist type figure, and even his friends abandoned him. Paine was left penniless and without anyone to turn to, as he faded into obscurity. Paine would still work, even becoming one of the first advocates of abolitionism. He also wrote a pamphlet, Agrarian Justice, that proposed creating an estate tax to fund a universal welfare program for the sick and elderly. Still, few wanted anything to do with him, and hatred was usually the only thing he got in return from so-called gentle Christians.
Thomas Paine was not a "sunshine soldier" this was a man who fought the good fight, who defended liberty for everyone, no matter the cost. He was a man who wrote in the common language, so every man, woman, and child could hear his arguments. Thomas Paine cannot be sugarcoated. His words are still available for anyone who wants to read them, and they still have the power to change minds in the service of liberty.