Once again, I'm not saying you have to believe in anything. Don't confuse me with Statler.
I am saying that most people are influenced by society. They are brought up a certain way and they believe what they are told. This goes for any kind of society, even your cannibal ones. Secondly, society, by its nature, is influenced in turn by the beliefs of the people. Thus the cycle continues and it is difficult to alter the framework of a particular culture's beliefs because they reinforce it themselves. That in mind, the "big 5" account for a lot of believers around the world. Moreso than any cannibal culture. This leads to my comment, which was that since a majority of people are believers, a majority of people influence society, and in turn are influenced by it, and you've got a culture (a different one for each region) that is basically in harmony with the local religions. You can say that religion requires sacrifice, but that's just more evidence that social morality can be influenced by religion.
It was a simple comment that while you may not ascribe your morality to a religous social influence, many people do.