I agree with you, however I don't believe it says that anywhere in the Koran. (I couldn't find it, but that just means I may be lacking in my googling skills)
Even if abrogation is not believed, which was first introduced not long after Muhammad's death, there are still an estimated ~109 violent passages in the Koran, as written by Muhammad. (Not like the Old Testament)
Quran (8:12) - "I will cast terror into the hearts of those who disbelieve. Therefore strike off their heads and strike off every fingertip of them"
I agree that there are very good and holy Muslims. What I believe though, is that they are good because they only acknowledge the good passages or what is right in the Koran.