Does our moral behavior derive from religion? Is it possible for us to be moral without being part of any religious group? One thing that is certain is that Western culture is based on Judeo-Christian philosophies. Almost every aspect of Western Culture is based Judeo-Christian beliefs from our legal system to our mores. However, our moral behavior did not all derive from religion. Social mores all derive from what is best for the collective. If everyone kills one another or steals from one another then it would be a detriment to the society. Therefore, governments exist not only to protect people but to punish people who violate basic social mores.
If you look at the Abrahamic religions (Judaism, Christianity, and Islam), there are certain traditions that you may look at as being uncivilized. In the old testament of the Bible a woman who cheated on her husband was to be stoned to death. In addition, if a virgin was raped, then the man who ravaged the virgin would have to compensate the victim's family and then marry the victim. It's traumatizing enough for anyone to be raped especially a young girl. But imagine tragedy of a young girl being required to marry her rapist and be a submissive wife to him; she would be victimized every day. Sadly, if she cheats on him then she would be stoned to death.
There was an article published in Psychology Today which stated that moral behavior and religion are not linked. People who are religious are more likely to commit acts of violence against one another than people who are not religious. It was also written in the article that religious people are more likely to go to war than people who are not religious; the author of the article mentioned that human history shows that religious people tend to have more combative impulses than people who are not religious.
Ultimately individuals determine what is ethical and what is not. The basis of ethics is to refrain from any behavior that compromises another person's physical, psychological, or emotional health.