Religion: I believe religion is a practice that teaches ways of good conducts and we all tend to found ourselves in a religion. I'm so sure all religion talks about good that leads man to the right track, correction from evil, love for one another, peace. But we still come across killings and all sort of different crimes in our society. If the society should practice our individual religion which they tend to belong, i feel the world would be a better place for mankind
Accourding to St. Augustine. In his "City of God" There are two peace in the world. Earthly peace and Heavenly. He said, heavenly peace is the best because there is no war, conflict or human disagreement in heaven. But earthly peace is the one we found ourselves. There is peace on the Earth but human with their accumulating ideas creates or causes disagreement among themselves. http://academic.brooklyn.cuny.edu/history/dfg/jesu/augcity.htm
In the state of Nature. According to Thomas Hobbs. Man is wicked, brutal, nasty and life is very short. That is to him human is beings are very wicked from birth. But Political philosopher, Rousseau Said, Human beings are good but it is the society they found themselves make them to be wicked. Someone that was good in the society became bad person because of what they did to him or her.
And also accourding to Karl Marx, Religious is an Opium. And what is an Opium? Opium is a substance which is used to make someone very weak for not to do what he or she supposed do to liberate his or her life from bondage. https://www.britannica.com/video/186414/opposition-religion-Karl-Marx.
Religious can't make peace because the people are control by the Politicians. And these Politicians are using divide and rule ideology. All the overseas are supporting the Political elites so, peace is absent in the world.