Everyone knows who the Gods are. But this is the study of their intricacies and details. Why they do what they do, how their laws have changed over the years. Maybe even what they look like!
0: You know the basics of religion, but the details are often missed.
1: Someone who serves as an initiate or has claimed themselves faithful to a priesthood.
2: Your average priest or priestess.
3: An Elder of a priesthood who has dedicated themselves to the knowledge of religion.
4: You have the knowledge expected of a High Priest. You know the ins and outs of most of the Gods.
5: Someone who knows more details than even the High Priest.
6: The Gods may visit you for clarification from time to time.