I would really like to see this movie again but I forgot the title to it. If you could help me figure out the name for it I would greatly appreicate it.

OK here's the details of the movie I do remember..
It was about a father and his two sons. (one of the sons is what the movie is named after if I recall correctly) the father believes demons walk the earth and he tries to capture them and kill them by dragging the "demons" back into his basement where he proceeds to kill them. He tries to get his sons to also help him in killing the demons but his children are younger at the time and can't be too much assistance. They start to believe their father has gone crazy..
I can't remember too much else but at the end I THINK one of the sons starts to believe his father and continues to kill the "demon"

Could be Frailty.

Yea that's definitely frailty with matthew mcconaughney

The Good Son