I was also thinking about the song, as it is great as few. I think the answer is quite simple, it just reminds me my past years. People so often these days are so confident, almost arogant, caring for their social position and reputation for all cost, thinking 'only me', I am the best, the one and the only, loosing from sight what is important (the others), being so focused on ourselves, becoming egoistic for things/people around us. We are happy, we are the kings of the streets, but this excitement based on 'the only me - the king' is like piles from sand, sooner or later the castle will collapse, the others will stop worship the king and become the revolutionarries who want your head. And his refering to christianity maybe is because the religion teach the others are more important than ourselves, the path to become the king, I mean, someone valuable is through caring after others. He didn't know about this, St. Peter would not call his name, but he understood and in the last line St. Peter will call his name.