We must understand that sin and evil often have no explanation. These are the sorts of things that go against human nature, since we are created in God's image and his law is written in our hearts. God provides us with a conscience and the ability to know the difference between good and evil from a very young age. It is only when we act against our better nature, by choice, that we allow evil to occur. This can happen in several different ways and demand a different societal response.
First, most commonly we see mental health as a contributing factor in violence. Those with mental health issues often do not receive the help they need and become isolated from effective support networks. Mental illness has the effect of preventing someone from perceiving reality as others do and thinking that violent behavior is the right way to act. Civil authorities should work hard to provide proper care facilities for those with violent tendencies and families should work to remove the stigma of mental health problems that often prevent people from pursuing professional help.
Second, political and religious discourse can lead to violent behavior when people begin to think that this is the only way for them to be heard or effect a lasting change. Instead of debating issues in the intellectual sphere, certain individuals will begin to focus their dissatisfaction on other people rather than the ideas they hold. Jesus reminds us to love each other, even our enemies. It is important to remove all "ad hominem" attacks in our discourse. These can be phrases like, "I wish that political party would just die off" or "All those religious types should be burned at the stake." It is always more productive to focus on the issues at hand rather than the people who hold them according to their own conscience and deeply held beliefs.
Finally, we all have an obligation to form our consciences according to the principles of both Natural Law and Christian ethics. Natural Law applies to all people, no matter their religious or cultural background. It is made up of principles such as the preservation of all human life; the existence of truth, beauty, and goodness; and the protection of the innocent. A Christian ethic refines these principles by looking at the human person as being beloved by God and called to a divine destiny. If our consciences are instead formed by anti-life principles, selfish aggrandizement, or violent behavior, it is no wonder that someone might see assaults and murder as a way to solve problems.
Too often we only attack the symptoms of violence, rather than the root cause. All people must work hard to build a respect for all human life and raise the level of discourse in our country so that the problems we face might be solved effectively. Let us also pray that violent hearts might be turned toward peaceful resolution