Correct me if I'm wrong but that movie isn't about post-Apocalyptic zombie hunting as it is a call to faith in the still, small voice of God.
There are moments when I expose the Barbie within - this is one of them. Can someone explain to this brain-like-a-gnat how this movie is a call to faith? You may flame as you wish, but please school me. Thanks.
SPOILER ALERT:In a flashback scene Smith's son (his son IRL, BTW) is making butterfly shapes with his hands.
Before Smith's family flies off in the chopper they say a very overt non-non-descript prayer.
When Smith meets the woman survivor she will not be shaken from her faith in a survivor's colony, claiming quite confidently that God told her so and reciting a list of coincidences she believes are indicative of the hand of Providence.
In the final scene the head zombie is smashing himself against the glass wall the glass fractures into a butterfly pattern. This cues Smith to think of his son's last night, then he remembers the butterfly tattoo on the woman survivor's neck.
Smith takes this to mean he is supposed to get the serum to the woman survivor--a pure act of faith on his part...and it seems he was correct.