Islam came after Christianity, so it's natural they would talk about the same angels, other religions use the same angels too. They are only ever messengers from god.
The quran is very similar to the bible, it was based on the same stories. The Arabian leaders / war Lords saw how the Jewish and Christian populous was so easily taught/led/manipulated/controlled by the individuals "at the top" they pretty much translated the same stories but added in their own historical figure (perhaps Muhammad PBUH was a famous war lord or great leader) to sell to their populous.
This is what I've come to believe from my research. Regardless of how things began and what has been done in their name, we are at a stage in civilisation where we have morals instilled via other means so religion need not exist in the mainstream. I'd say the UK is probably one of the most advanced political structures in regard to this, from my limited knowledge.
Eh?Had to because the muslims started it anyways.