Look, if he's Muslim, he has the same right to be president as anyone else. But if he can't treat other religions equally, this is a problem.
Paul has emphatically stated that he believes the principle of pre-emptive war goes against the 'Just War Theory' of Christianity. He has also stated that being in perpetual war does not go along with Christ's teachings. So you are wrong, he seems to be the only candidate who actually CARES about our foreign policy being in line with Christian values.
Here's a clip of him at a debate speaking about pre-emptive war.