Frailty

Frailty is a 2001 movie directed by Bill Paxton and starring Paxton, Matthew McConaughey, and Powers Boothe.

Fenton Meiks (McConaughey) comes to a FBI agent (Boothe) with information about the notorious God's Hand Killer, who has been terrorizing the state of Texas. Through flashbacks, we learn about Fenton, his brother Adam, and his father (Paxton) who has a religious experience that plunges the entire family into turmoil. The father gathers his sons together one morning and tells them they are now soldiers in a heavenly war, and are charged with destroying demons on earth. The revelation splits the family: Adam and his dad are on one side, believing they are destroying demons; meanwhile Fenton believes they are murdering innocent people and is torn between loving his father and thinking he's completely off his rocker. Fenton makes a fateful decision and has come to the agent's office to relieve his guilt and confess his family's buried secrets...

...Or Has He?

The movie contains examples of:

 * An Axe to Grind:The axe is inscribed with "OTIS". Some fans think this is either the father's first name, the name of the ax, or an acronym meaning "Only The Innocent Survive".
 * Word of God is that the only reason "OTIS" was put there was so that you'd know at the end of the movie that it's still the same axe, making "Only The Innocent Survive" more of a backronym.
 * Cassandra Truth
 * Christianity Is Catholic: Averted. One of the deleted scenes reveals that the family is Baptist. Bill Paxton says that he cut the scene because he wanted them to be, in his words, "generically Christian."
 * The Family That Slays Together
 * Flash Back: Most of the movie, really.
 * Foreshadowing: The song the kids are singing at the beginning.
 * Heel Realization: Subverted like whoa. At one point the father has Fenton build a dirt cellar and locks him in it so that Fenton can find his faith.
 * Killed to Uphold the Masquerade: The sheriff.
 * Knight Templar: The dad. He even murders an innocent sheriff to prevent him from finding out about the plan, and comes within a hair of planting an axe in his son.
 * Only Sane Man: Fenton Meiks in the flashbacks.
 * No Name Given: Bill Paxton's character is never referred to by name.
 * Mission From God
 * Punny Name: The Meiks shall inherit the Earth.
 * Room Full of Crazy: bedroom.
 * Serial Killer Killer: But then again, Unreliable Narrator.
 * Telepathy: The father claims to have the ability to see people's sins by touching them.
 * Tomato in the Mirror:
 * Trouble Entendre: "I promise to God I'll bury you here."
 * Twist Ending:
 * : And how!
 * Vertigo Effect: When the FBI agent meets the Sheriff,
 * Vertigo Effect: When the FBI agent meets the Sheriff,