'Consider: every devout Muslim has the same reason for being a Muslim than you have for being a Christian. And yet you do not find their reasons compelling. The Koran repeatedly declares that it is the perfect word of the creator of the universe. Muslims believe this as fully as you believe the Bible's account of itself. There is a vast literature describing the life of Muhammad that, from the point of view of Islam, proves that he was the most recent Prophet of God. Muhammad also assured his followers that Jesus was not divine(Koran 5:71-75;19:30-38) and that anyone who believes otherwise will spend eternity in hell. Muslims are certain that Muhammad's opinion on this subject, as on all others, is infallible.
Why don't you lose any sleep over whether to convert to Islam? Can you prove that Allah is not the one, true God? Can you prove that the archangel Gabriel did not visit Muhammad in his cave? Of course not. But you need not prove any of these things to reject the beliefs of Muslims as absurd. The burden is upon them to prove that their beliefs about God and Muhammad are valid. They have not done this. They cannot do this. Muslims are simply not making claims about reality that can be corroborated. This is perfectly apparent to anyone who has not anesthetized himself with the dogma of Islam.
The truth is, you know what it is like to be an atheist with respect to the beliefs of Muslims. Isn't it obvious that Muslims are fooling themselves? Isn't it obvious that anyone who thinks that the Koran is the perfect word of the creator of the universe has not read the book critically? Yes these things are obvious. Understand that the way you view Islam is precisely the way devout Muslims view Christians. And it is the way I view all religions.'
Sam Harris- Letter to a Christian Nation