As people said, its about the Columbine shooting, a man asked Cassie if she beleived in god, if she said no he wouldnt kill her, if she said yes he would. She says yes he kills her. Then he asked that to Rachel, she says yes, he shoots her, but she doesn't die, he asked her again, she still says yes, and he shoots her again and she dies. Its about how if you really truly beleive in something that you wouldn't betray it for anything.
Love this song, love Flyleaf they Rok.