but that's because almost all of them ignore most of what's written in their holy book. The corresponding fraction of people who call themselves Muslims is far smaller.
Most people of whatever faith give lip service to their religions while taking care of the day to day needs of raising families and so on.
I question that on average most Muslims know more about their holy book then other people on average know about their holy books.
People are people and it had always amused me that as an atheist I often know more details of their religion then they do.
The ten commandment story is one of the most amusing as when Moses came
down from the mountain top with the commandments including the one about not killing then after finding they had sin in a big ways he have his closed followers killed at random under they could no longer move their swords.
I always laugh when people pointed to the ten commandments as something we should all respect when Moses himself did not respect it
Moses stayed on the mountain for 40 days and nights, a period in which he received the Ten Commandments directly from God. Moses then descended from the mountain with intent to deliver the commandments to the people, but upon his arrival he saw that the people were involved in the sin of the Golden Calf. In terrible anger, Moses broke the commandment tablets and ordered his own tribe (the Levites) to go through the camp and kill everyone, including family and friends, upon which the Levites killed about 3,000 people, some of whom were children. God later commanded Moses to inscribe two other tablets, to replace the ones Moses smashed, so Moses went to the mountain again, for another period of 40 days and nights, and when he returned, the commandments were finally given.