The attempt to bring European Christians together forced one reformer, Caspar Schwenckfeld, straight to the fringe.
German theologian and resister
How did the church come to understand Christ as fully God and fully man? Stephen Need is an excellent tour guide to the early church councils that debated the core issues of Christian faith.
The vision of John Comenius and the story of the Unity of the Brethren give us a good way to test a hypothesis.