The Dark Ages didn't happen because Christianity started existing. The Dark Ages happened because barbarians began to take over Ancient Rome causing it to fall. This left us with uneducated and unorganized barbarians who didn't know anything. Therefore, humanity had to kind of start from scratch.

Christianity was a good thing and a bad thing during this time period. Christianity was good because it put the barbarians in order. It helped to organize them better and to act more civil. But, Christianity was a bad thing because of the Crusades.

You can't really say that the world would have been better off without religion. Yes, the followers of said religion have done bad things, but the religion itself has helped people too.

So, why do we argue over this? I am an Episcopalian Christian. I believe what I want to believe. I don't care what other people believe. If somebody is an atheist or a Muslim or a Hindu, I don't think anything of it (in case you didn't read this correctly, this comment was not a 'You should be a Christian comment' it was a 'Religion was good and bad, but whatcha gonna do? Get over it' comment). Why can't everybody be the same way. Let's all just coexist.

Incorrect. The Church actually preserved a lot of knowledge after the fall of the Roman Empire that would have been lost otherwise.