He isn't a Christian, he's a leftist. Were Kerry's or Clinton's beliefs 180 degrees from Christianity? Were they Muslim?
Kerry wasn't born a Muslim. Obama was. That is the same as being born a Jew. You don't shed your Jewishness merely because you don't really subscribe to all the religious materials. Likewise you don't shed your Muslim status merely because you believe that Jesus was a great moral teacher. You have to renounce Islam or you have to claim (as Christians do) that Jesus Christ is God in Human Flesh. That will end your status in both Religions. Has Obama ever acknowledged the Deity of Christ? Has he renounced the faith of his Father?