Religion is seriously complex in Henry VI, Part 1. What's going down? Catholic Christianity is the religion shared by both the French and English. Should be simple enough to keep straight, right? Medieval Catholics believe in God, whom they see as good, and in the devil, whom they see as bad and dangerous. But it's more complicated than that: Even if they share a religion, the French and English are opposed politically—and they both want to claim God is on their side.
Adding to the mess is the fact that even though the French and English were both Catholic when the events of the play happened, this wasn't true when the play was written. By then, the English had mostly become Protestant, at least officially.
And there were some big differences between Protestants and Catholics, especially when it came to praying to the Virgin Mary, Christ's mother (in short: Catholics did, Protestants didn't). So sometimes the play kind of acts like the English are Protestant, even though they were technically Catholic at the time that the play's action unfolds in. Suffice it to say that Shakespeare knew how to please his audience.
Questions About Religion
Why are the English convinced from the beginning that Joan is a witch instead of a saint?
Why do the French describe Joan as a saint and also wonder if she might be having an affair with the French king? The two things seem contradictory in Medieval Catholic thought.
What is the extent of Joan's supernatural powers?
Does being a churchman allow Winchester status and power he wouldn't have otherwise?
Chew on This
The French want to believe Joan is a saint, but they aren't completely sure.
Joan's powers aren't actually supernatural. Most of them could be pulled off with cleverness and luck.