Thomas Paine (the author)
The author of this nonfiction, argumentative work, Thomas Paine was a crucial figure in the American Revolution and the development of the United States in the later eighteenth century. He was an adamant Deist, and his religious views were held to be controversial at the least. In The Age of Reason, Paine makes an argument for Deism by attacking the foundation of the orthodox Christian religion as seen in the Bible and the institution of the Church.
God
In Christian doctrine, God is the creator of the universe. He is typically seen as active and directly interventional in the lives of humans on Earth, as seen through miracles and the sacrifice of Jesus. Paine, however, characterizes God in a different, notably Deistic way: as an impersonal, impartial watchmaker who made the universe, and who now just stands back and watches it run.
Jesus Christ
In the Christian church, Jesus is seen as the Son of God made flesh, both fully God and fully man, who died to redeem broken humanity from its sinful nature. Paine, however, rejects this claim as absurd and unprovable, instead painting a picture of Jesus as a good moral teacher who was incontrovertibly a historical figure, but who made no claims to godhood - these were forced upon him by later writers.
Satan
Satan is traditionally seen as the antithesis to Jesus: a fallen angel who rebelled against heaven and caused the fallenness of creation. He is said to have tempted Eve in the Garden of Eden in the form of a serpent, starting the cycle of brokenness and restoration completed by Jesus. Paine, however, argues that the character is Satan is ridiculous; there isn't enough evidence to assert his existence, and his actions aren't well-motivated, so Paine essentially discredits him altogether.
Moses
Moses was one of the Jewish patriarchs, an important figure in the history of Israel and the lineage of Jesus. He led his people to the edge of the Promised Land, having left his homeland at the call of God, and God's covenants with Moses are among the most important Biblical covenants. He is said to have written the Pentateuch (the first five books of the Bible), but Paine takes up this claim, arguing that the evidence (which is meager in the first place) seems to point the other way.
Galileo
Galileo Galilei was a Florentine astronomer and mathematician who discovered that the solar system revolved around the Sun, not the Earth. Because of accepted doctrine, he was persecuted by the Catholic Church for his "heretical" theories, and he was forced to recant. Paine essentially equates himself with Galileo, pushing back against ecclesiastical dogma in a controversial way that actually contains the truth.
