Things aren't always what they seem in "Frailty"

Things aren't always what they seem in BILL PAXTON'S "FRAILTY," and the actor/director seems to delight in confounding our expectations.
A friend lent me the DVD for this 2002 film, and I watched it last night.
Paxton stars as an otherwise ordinary single father of two boys in Texas who suddenly begins receiving visions. God, he tells his sons Fenton and Adam, wants the family to destroy demons who have been unleashed upon Earth in preparation of Judgment Day.
The "demons" look like the people we see every day. Paxton's character tells his boys he can tell their demons, though, when he lays his hands upon them and their evil deeds are revealed.
Young Adam (Jeremy Sumpter) believes his father, while young Fenton (Matt O'Leary) is beyond skeptical: Fenton thinks his father is descending into murderous madness, especially as the number of destroyed "demons" begins to mount.
At least, that's the tale a man calling himself Fenton Meiks (Matthew McConaughey) tells a doubtful FBI agent (Powers Boothe) assigned to a baffling case of serial murder.
"Frailty" is harrowing at times, as Paxton's everyman persona (he's a small-town mechanic) is cast at odds with behavior that includes locking the disbelieving Fenton in a cellar.
My advice: If you watch it at night, be prepared for an edge-of-the-seat experience. And prepare yourself for a few surprises.