Cynosure

Think about it. Why would a person who believes in God and the afterlife (including eternal damnation), commit murder as one of his last acts on this world, and then immediately afterward commit suicide? Especially if that person is a self-proclaimed Christian who is knowledgeable about the Gospels?

A. That person is deeply angry and resentful toward God for not handling things (i.e. mankind and the world) the way that person thinks they ought to be handled. Thus the murder and subsequent suicide are final acts of ultimate rage and rebellion.

B. That person is deeply angry and resentful toward his religious family members and his fellow church-goers, what with their hurtful judgmentalism and their treacherous hypocrisy. Furthermore, that person is deeply depressed and self-centered, and has not found in his church what he was desperately (and perhaps unrealistically) looking for. Thus, that person commits the acts of murder and suicide as an ultimate "fuck you" to his family and his church.

C. That person is so furious to prove God's existence – or, really, to force God to prove Himself – that he psyches himself into committing some of the most despicable acts he can imagine, hoping that God will reveal Himself and somehow stop him.

D. That person doesn't really believe in God and the afterlife, and therefor doesn't believe there will be eternal consequences for his heinous actions.

E. All of the above. (Yes, some of these reasons can seem contradictory – but that's the way humans are.)