The light that shines in our hearts is what we should let guide us in our everyday decision making. If our hearts had unconditional love, then there would not be any space left for hate or evil. Love in my opinion is more powerful than any hatred. In the realm of ethics, we are told to avoid murder, thieving, lying, and adultery. These are minimum guidelines, as we realize if we reflect on how much better, the world would be if they were universally honored.
Evil is the absence of empathy.
It is hard for a person to know the meaning of why suffering and evil occur. When your heart is full of light, it is impossible to think negative thoughts. When someone experiences life with empathy there is an internal knowing of compassion and understanding for others. There are always going to be situations in our lives that we cannot comprehend or should even try to comprehend because some situations just are not to be explained in context of why things happen in our life. That is part of the mystery of life.