If you are suggesting that a person's relationship with God (whether you believe there is a God or not is irrelevant in this argument as the subject is "the world with or without religion, which is better..") is better than one where a person has no relationship with God then you automatically are making the assumption that all faiths of every kind are bad and can have no good effects on man kind. Yes for christians there has been some bad points in history for sure, but out of those came lots of good things. The reformation being just one example. While there are many generally ignorant christians out there and misrepresent the truth about the bible and God, that doesn't mean the bible and God are bad. Never judge a product just by the spokesman.
Your thesis contains the word "better" please define that word. As it is right now, I have no way of defining what you mean by "better". The statement "A world without religion is better than a world with religion" is declarative. Why do you say a world without religion is better than a world with religion?