I hate to break it to you, but what you are describing are the natural failings of human beings. We are capable of the most awful acts and thoughts and will always seek to come together in a way where we feel united. Often the way we feel more united with our fellow men and women is our shared prejudices against what we perceive to be a threat / difference to our narrow world view. There is nothing more threatening to a group of people with certain powerful beliefs than those beliefs being questioned by another set of people with equally powerful beliefs, it becomes impossible to reconcile. Therefore human beings over time have found ways to justify persecuting other human beings even though they may have some kind of faith that actually teaches the opposite. Read some history, war can be defined as religious intolerance. If you are looking for true peace you must free yourself from the idea that you need to believe in a higher power, then you will see that it is actually men that cause the problems, but also men that can solve them! Men and women are capable of many good things and many bad things without even bringing the idea of god into existence. 
