To clarify a couple issues, let me explain.
First, the play was not based on Cassie Bernall's life story at all. The development of the play began within a few days after the Columbine tragedy with the awareness that at least one of the victims (Rachel Scott) was a Christian and that she had actively shared her testimony with others at her school.
Secondly, many different groups used the Columbine tragedy as a means to discuss problems in society in general. Some focused on the need for gun control, some on the affects of peer criticism and bullys in high schools, and some on the failures of social programs to reach troubled youth. I took the view that the killers relationship with God was an important factor in what ultimately happened. If this makes me guilty of "vampirism", so be it. But I accept this label only to the same degree as others who looked at the Columbine tragedy and tried to make some sense about why it happened.
The cause of this tragedy was complex. It was a combination of circumstances and decisions that ultimately culminated in two teen-agers taking out their anger on their school mates. There's is no one thing we can point to and say "this is what caused it to happen". It was a variety of things.
I chose to look at the tragedy from a spiritual point of view. I felt that if the killers had trusted God to help them with the problems they faced and then listened to God as He guided them, they would have acted differently. As I said before, all murders are the result of rejection of God. That is because God cherishes all life and desires that we cherish life just as much as He does. Murder is an example of what happens when a person turns their back on God and the things that God values. The killers reacted as they did not because they didn't believe God existed, but because they turned their backs on God and the help He offered them.
Someone asked about truth. The truth is this: God does exist. He also loves us. He wants to have a relationship with us that results in a fulfilling life. He also wants us to spend eternity with Him.
The problem is that we are imperfect. The Bible calls this sin. This sin separates us from God. This separation keeps us from experiencing the fullness of life God wants for us. But what's worse, if we die separated from God, we will live eternally apart from Him.
Because God loves us, He did something to restore our broken relationship with Him. God sent his son Jesus to die on the cross to pay the penalty for our sin. God accepts Jesus' sacrifice as "compensation" for our imperfections and our sin. I am redeemed now not because of something I've done to earn God's favor, but because Jesus died for me on the Cross.
By the way, this is not true because I believe it. I believe it because it's true. I've read many books that have tried to discount what happened 2000 years ago in Jerusalem. But an objective look at the historical evidence validates that Jesus existed, that he claimed to be the son of God, that He died on a cross, and that He rose from the dead. These facts and these facts alone validate that Jesus is the only means to bring us back to God and redeem us from our fallen natures.
So that's what the play is about. Not about "Cassie" or about "atheists" or about "christians". It real focus is on the choices we all make about God, the consequences for the choice that at least one person ("Jason") made about God, and ultimately the eternal consequence of accepting or rejecting the salvation that God offers to everyone of us.