If you notice, Islam has the best and most devoted followers. Not saying ALL Muslims follow their religion properly (lets not mention those terrorists, they clearly are sick in the head) but other than that most Muslims take their religion seriously in comparison to other religions. I know Christians but they don't even follow their religion properly, they call themselves "Christians".
Why do you think a lot of Muslims love their religion? Isn't it because they truly know it's the correct religion?
Why do you think a lot of Muslims love their religion? Isn't it because they truly know it's the correct religion?