Christianity is only mentioned three times in the article so the entire article can't have an anti-christian tone.  Two out of three times, the mention of Christianity is in reference to Christians and conservatives blaming popular culture for the massacre, which actually did occur (so it deserves mention).  The only bias I do notice is the mention of using Cassie Bernall to boast popularity for their faith despite the truth of the matter, but this can be easily changed to an NPOV without deleting the fact.