There's no limit to the greed and selfishness of man, so to get most people to behave nicely towards others, you need to approach the idea through their selves.

For example, you could tell them that if they're nice to others, after they die, they'll go to an awesome place that's just like whatever they really want the most, and that in this wonderful place they can partake in as much beer and 17-year-old virgins as they want.

That could work! But it's still about everyone's personal gain. Yes, religion. I don't remember the details though, since it's been more than 20 years since my last brainwashing session at school. Around the age of 10, I gave it some thought and figured that it would be impossible to prove it either way, so I just wouldn't believe in God unless he showed himself to me.

Some people are more capable of thinking about things from someone else's perspective than others, but even the compassion-impaired among us can reach the right conclusion through themselves. "Would I like it if someone stabbed me in my face? Hmm.. No. That would definitely be unpleasant, so maybe I shouldn't stab anyone..", or the less favorable option you referred to: "If I stab that guy in the face, the police will probably catch me and I'll get locked up. Being in jail restricts my ability to grab women's asses on a crowded subway train, which is my favourite hobby, so I'll just have to not stab him then".

Don't you use your brain and common sense to make all decisions, whether you're religious or not?

I hope so! But religion sure tells people what they can and can't or shouldn't do. For example that if a woman is adulterous, she should be stoned to death. Sure, that's a different, much more harmful set of fairytales, but it's a religion. You could say that religion is a system of enriching and empowering a group of people, letting them strut around in capes, acting all high and mighty, and making sure they get away with fucking little boys or girls (<-Islam). Of course, maintaining this system requires a vastly larger group of people that's kept mired in a lower level of consciousness, doubting, hating, and rejecting anything and everything that hasn't been deemed good and proper by the former group.

Example: Religion doesn't say anything about illegal downloading.

True, they'd have to update their fairytales once again, which would be difficult at this point.

Remember how parts of the bible were once used to justify slavery? Does anyone try to use the bible to support slavery anymore?

Religion was used to the advantage of that small group of people, who just happened to like having slaves. I've only been to one city in South-Korea, but that one was full of little churches, and the general populace believed that as good little Christians (more than half of them), they should give around 10% of their salaries to their churches. Kind of shocking, actually.

Some Christians learn to adapt to having members of the homosexual community in their congregations. Others can't deal just yet cause people dislike change.

They just dislike anyone who's different from them and they're insecure about their own sexuality.

I believe in moral absolutes. But that's only assuming the existence of God, because in that sense morals are defined by the nature of God.

What does that even mean? See, that's what happens with religion. You try to adapt your own reasoning to the fairytales, and the result is hand-wavy at best.

What if there is no God? How "would" you view morals then?