Very Good
Rather than speaking against God, i think this story is speaking against those people who expect to make a bargain with God to solve all their problems and end up losing something valuable. Though the warrior said, "help us to defeat your enemies, e probably only wanted to save himself, and rather than solve his own problem he turned to God for help and believed he had to offer something in order for God to help him, even though he could have just made a simple prayer, which God would have answered even without the need of a girl's soul.
Sapphyres pointed out that in the story of Abraham, God stopped Abraham from offering his son, but that story is different, for in that case God asked Abraham for his son. In this case it was the other way round, the man offering his daughter. If anything the difference shows us that God does not want people to make human sacrifices.
In the story of Job, the children which God gives Job are Job's original children, plus two more.
Sapphyres was right about doing the right thing for it is the right thing, and not doing it out of fear of burning in hell. I would also like to point out that i am a Catholic (Roman Catholic to be specific)
Nice movie, with a deep meaning.