All of the dialogue seems quite wrong to me. The relationship between the Christian characters and god seems to be too personal and unmediated, and the hierarchy too informal. It is like the religious experience of a modern Christian. For example Saints are never mentioned, and the lead character prays on his own, directly to god asking for forgiveness and a sign. There are no relics or rosaries. I don't get the feeling of a great chain of authority, with your humble man right at the bottom, and god far away.
The relationship between faith and violence is obviously an important modern issue, and the question of whether faith is tested by resistance to pain is a significant one. But this film does not really explore how that relationship operated in the Middle Ages as an authentic historical period. That doesn't necessarily make it a waste of time, just depending on what you want.