Religion invokes a One-sided World View

[Wyrd of Gawd]

Certainly they are often able to dismiss in all of five seconds the devoutly held beliefs of people from other religions as "wrong" yet will utterly fail to notice the exact same flaws in their own beliefs.

Christianity and Islam particularly have a very clear divide between the in and out group. The out group will receive worse treatment after death, and not only that, they deserve it, just for not picking that particular religion out of the infinite number available.

It adds to this instant dismissal, that even though this effects all religious peoples a majority of the time, the fact that christianity is most prominent in the US, and Iraq in a few different countries but that these religions are almost on opposite sides of the world, or might as well be, means that the average christian will not hesitate for a second before dismissing the validity of a muslims belief.

Christians were fighting each other within three minutes of the founding of Christianity about which had the right beliefs.  Muslims were fighting each other within two minutes about which sect was the right one.  The reason for that is religions offer con men the opportunity to be the king of the con men if he can eliminate opposing groups of charlatans.  The New Testament gives several examples of this.  The Koran mentions the division of Islam into several competing sects, even when Mohammed was supposedly alive.