My world is based heavily on Medieval Europe. The political, economic, and social organization of society are those of the mid 1400s. I'm stuck on building my dominant religion. I want to incorporate the institutions of the Medieval Church (monastic orders, bishoprics, parish priests etc.) without transplanting the whole religion. Some of the elements I want to incorporate are the military monastic orders, the conflict between religious and secular authorities, and the relationship to religious minorities (Jews, Muslims, and heretics). I feel like a monotheistic religion is the only way to pull this off. Polytheism seems to lend itself to a more decentralized religion, with different people favoring different gods. I need to figure out away to bring in the institutions of Christianity without brining in the dogma.