A possible anti-war film?
Antonious sacrifices his life in order to save the artists Jof and Mia. Jons returns from the Crusades unhappy with the fact that he participated in it. The war destroyed their faith in God, and while Jons did not seem intent on asking the more serious questions about the existence of God, Antonious could not stop asking these questions.
I think that Jof and Mia were made out to be virginal-like (Jof admits that he didn't touch any alcohol at the inn, and if I remember they are wearing white on more than one occasion). Therefore they did not sin, and had a very strong faith.
So I think that Bergman was saying that wars do not help humanity, they only make us kill innocent people. But art (and artists) can inspire even the most conflicted people to do right (Antonious being inspired to save Jof and Mia and the baby) and help humanity.
I hope that makes sense
J Dilla Changed My Life. Rest In Beats.