LB:
The above point implies much knowledge & experience on your part. I want to take a moment to catalog just how much knowledge & experience the above point would require a person to have.
I want to take a moment to catalog my own experiences regarding this:
1. I've had a lifelong interest in spiritual matters.
2. In the course of studying religions in college just for fun, I received nearly enough credits to earn a bachelors degree in religious studies.
3. My first job out of college was developing products in the publishing house of one of the largest Christian churches in the United States. If you think you can sell product to your customers without having an intuitive feel for what's on the minds of 51 percent of your customers, you would be delusional.
4. My second job out of college was working for a press specializing in alternative spiritual publishing. This was a fantastic opportunity to pursue my interest in world religions.
I can't say that I understand the majority of Muslems thinking, but I know enough about them to say that the professional Muslems I've encountered in my professional life seem about as different as the loony tunes storming the embassies as the educated, professional Christians I've worked with intimately differ from the PIPs (People in the Pews, or as some of the less charitible clergy I worked with called them, the lower Christians) in mainstream Christianity.
After a lifetime of living with, studying, and working with Christians I can say with some authority that yes, most Christians don't seem to understand the basic tenents of their own religion. Ask your average Christian to define grace, the central tenent of the Christian Church, and he or she will probably tell you that Grace is the chick who lives with Will on that gay TV show.