Lamb of God

 When Mitchell Wallace halts his suicidal plunge from an overpass to help a little lamb who has wandered onto the busy interstate below, he sets into motion a chain of events that alter his life as well as the lives of his best friend and his sister.

Together, they are thrust into a terrifying and hilarious battle between good and evil that has them facing off against a band of shadow demons, violent giants, a horde of homeless undead, and satanic forces bent on claiming the earth as their domain.  
On a roadtrip from hell, the trio of unlikely heroes and a bible-quoting magical lamb race against time to find the mystical "Lost Staff of Ba'al", the only thing that can save the earth from a demonic undertaking.

If they don't kill each other in the process, they just might save the world.