Obviously religion is going to cause conflict, and even what we justify as totally unnecessary deaths, which strongly supports the argument against religion. If we had no religion the world would be a better place in the sense that nobody would fight for their religion. The world would also be a worse place because (probably) over 90% of people act in a different (better) way then they would if they didn't believe in heaven or hell.
Did you watch the video? One of the techniques used several times was to assure the convert that all they had to do was believe a small set of things (none of which had anything to do with being a good person) and they were *assured* entry in heaven.
Ask a typical Christian if the Bible is the revealed word of a living God who holds their eternal salvation in his hands and they'll say "yes". Then ask them if they've ever read the whole thing or bothered to understand what each section was saying. Their religious beliefs have no real effect on their behavior.
Perhaps without religion, people would have found the right reasons to be better people. And no one would have to get nailed to anything. (Perhaps not. My point is simply that it's easy to see the advantages of the actual and easy to not see the advantages of the potential. For example, NASA frequently talks about the technological advances they are responsible for. But who knows what advances the money spent on NASA would have brought if spent elsewhere.)
Also, I think religion is still a horrible evil, even if it did make 90% of people act better (which I do not accept), because of the people who fight and kill for religion. Think about a really good doctor, say one so much better than most other doctors that he saves an extra 20 people per year. However, he does ask in exchange that he be permitted to murder 1 patient per year. So, this doctor will save 19 lives per year. However, he does murder one random person, who otherwise would have lived. Maybe you're enough of a pragmatist that you'd reluctantly hold your nose and hire this doctor. But I don't think you would argue that he's perfectly entitled and morally justified in killing one person, given that he saves 20.
You can't make up for the bad with good that way.