If you want to know what kind of people follow a particular religion, don't study its tenets, its beliefs, its values, or its ethics. Look instead for its sins.
Christian sins include gluttony, sexual misconduct, wrath, envy, etc., and you will find no people as fat, perverse, angry, and resentful as Christians. In the Church of Satan, you find the sins of stupidity, counter-productive pride, lack of perspective, etc., and its members invariably behave as if these sins were virtues. Within Islam, you find sins such as associating anything with Allah, theft, gambling, and backbiting, and I hardly need to mention which behavior comes to mind when you observe muslims.
And so it is: religious sins describe the people that the religion fosters or attracts. If you find cowardice among the list of sins, don't expect a follower of that religion to stand up for you when the going gets tough; if stupidity is a sin, you can safely bet your money that the religion attracts mostly uneducated people; and if lust is a sin, keep a watchful eye on your children if you leave them among followers.
