I don't think the lyrics are pro-Christian... they just seem very tongue-in-cheek. They're supposed to reflect the hypocrisy of so many big names who were religious and often seemed to betray the values their religion holds. Good song, good message in my opinion.
Whether or not this song's lyrics are in a sense of irony doesn't even matter to me as much as how disgraceful it is so many people "lose respect" for a band or are disgusted with them just because a song's lyrics might be showing a pro-Christian attitude. I bet you do not feel the same over all the pagan metal bands, and I sure don't... You guys need to grow up.