Also, if he was Christian, his songs would glorify God which would cause him to lose 1/2 of his fan base and have to down size his house and car. He has a lot of power over young girls, I believe hearing that girls were cutting themselves over Beiber smoking- I'm not sure if that is true or not, but it wouldn't be not surprising. That would never happen with a Christian artist or band that is centered on the message of God and Christ.
Call me skeptical, but a part of me wonders if someone was in his ear about trying to reach more of a fanbase by being 'spiritual'. I may be wrong tho. Many secular music artists, mention God and Christ in their songs (take Kanye West and his song 'Jesus walks'), but do they live out their faith? In the end, I don't know their hearts, they could be devoted to Christ- more devoted than I am even- but I think actions speak louder than words.
For me though, I will stick to artists and music that glorify God through praise music, Christian rock and screamo.