This is not an easy writing for me because what I will say will be foreign to so many people and it will challenge the beliefs taught by many religions. However, if the key is to understand the senseless, then the truth must be told. Tragically, the church has kept the truth of spirituality away from the masses in order to maintain control over them. This is not a welcomed fact since it undermines your trust and belief in the church. If what I write rings true for you, then it is for you. If it does not ring true for you, then it is not for you. I will share some of my truth with you.
If you believe God knows all things, then God already knew Dylann Roof, the South Carolina young man who murdered 9 black people while at a church service, would kill all 9 of those people long before it happened. Why would God allow such seemingly evil things?
1) What looks evil in the short term may work for the good in the long term. For example, many white people are now motivated to question their beliefs and if people choose, many other positive changes in society can be made.
2) It is allowed to bring a problem to the attention of everyone so that it can be addressed and solved. For example, people are asking what caused this young man to kill all of those people? How can this be prevented in the future?
3) Each person has a task of developing a conscience. This only comes through experience and personal choice. Hopefully, Dylann Roof will look at his actions and see that they were wrong. That his beliefs were wrong. It is his choice to do so or he can choose to not grow. One can go as far as to say that those 9 people whom he killed sacrificed their lives to give him and others an opportunity to grow and to bring attention to a greater problem so it can be addressed. Often the best and long lasting lessons are the most painful ones.
I will stop right here. There is much much more to help you understand though. Ask and you shall receive.