The Movie 'Frailty'

'Frailty' is a movie I watched yesterday. The story is about a father of two sons who saw a vision of god. He claims that god want him to destroy the demons in the world. Not long after that he told his sons the god already give him a list of the demons' names. Then, he go to destroy them one by one after god gave him weapons to do it.

However, the eldest son, about 12-13 years old, does not believe it. He thinks his father is killing innocent people and is a murderer. Then he killed his father when his father forced him to kill the so-called-demons that resemble humans. But the younger son sees his father as a hero and he continues his father's mission. He also killed his brother who, according to his father, is also a demon.

This movie is so confusing. I don't know who is right or who is wrong. Well, I, personally, don't think that killing people just because of the crime they did is a right choice. Why can't the father just investigate the crime they did and report to the police? He didn't need to kill them, it will make him just like them.