The Terrifying Brilliance of Islam
Saturday
A religious doctrine is a collection of ideas. These could be customs, words, beliefs, etc. A religion is not a single idea; it is a collection of ideas. The collection of ideas that make up the religion of Islam makes Muslims behave and feel as they do.
Collections of ideas compete with each other in the same way that collections of cells (organisms) compete with each other. And because idea-collections compete, and because new ideas can often be added or subtracted from the collection, and because some collections gain more believers than others, collections of ideas can actually evolve.
Let's look at how religious idea-collections evolve and compete. To begin with, let's assume we already have a religion established. It already has a holy book and millions of people are already believers.
And then there is a slight variation...
Let's say the original version had a "live and let live" attitude, and never tried to encourage its followers to bring in converts. But then someone comes up with the idea that if you can persuade a non-believer to become a believer, you earn some sort of spiritual merit. You are saving souls, and your chances of getting into heaven are better.
http://www.citizenwarrior.com/2009/05/terrifying-brilliance-of-islam.html