Jerusalem, Antioch, Ethiopia, Egypt, Rome, Alexandria, Athens, Thessalonica, Illyricum, and Byzantium. Early Christian centers distinguished themselves with relics of the Apostles and other heroic saints. Judaism is the direct ancestor of Christianity.
It is arguable that the Greek mystery relgions are an ancestor or are the set of metaphors and the language used to express semitic concepts to the Greek mind. Gnsoticism, Nestorianism, etc are arguably descendents. Just as there are new age religions making Jesus one of a pantheon of Gods, there were similar practices at the beginning of Christianity.
It would be wrong to call these religions that adopted Jesus as "ancestors" of Christianity. Jersey, I was looking for that, but the only one I could find was annotated in Chinese or Korean.
There was no such thing as Catholicism before the split with the Eastern Orthodox Church.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.