Religion Vs Cult: What's the difference?

I do have a good knowledge of the Koran because I've read it cover to cover, just as I have the Bible (in the military, there is a lot of downtime where you can either: A.) whack off, B.) lift weights, or C.) read books, I chose options B and C with only an occasional amount of A.). I don't claim to be an expert, but I do have good understanding of Islam.

 

So there's nothing in the Qu'ran that says killing murder etc is bad? Nothing at all?

 

Cult: A small, unpopular religion.
Religion: A large, popular cult.