Why do people think Obams is a Christian?

Obama is the only President we've ever had who celebrated Ramadan in the White House. Also, the only world leaders he's given state dinners for were from Communist or socialist countries. He's insulted the National Day of Prayer, Memorial Day, and the only "Christian" church he attended was the radical Jeremiah Wright's church that preaches Black Liberation Theology. He has bowed to the king of Saudi Arabia, but he offended the Queen of England and the President of France by giving them insulting, self-serving "gifts". He has slipped up and said there were 57 states (there are 57 Muslim states). As President, I would think he ought to know how many states he controls. He also defends Islam if anyone criticizes it in any way..