Hate makes us do something to hurt others, indifference allows us to do nothing to help others. Hate is what makes people do things like the terrible shooting at the Jewish Community Center in California, the murder of the abortion doctor in New York, the dragging death of the black man in Texas, or the slaying of the gay student in Wyoming. Indifference is closely connected to hate, but is one step further down the ladder toward total evil. Indifference usually manifests itself when we know of someone else's hate and just let it happen. Indifference is not doing anything when something cries out to be done.
Indifference is the silent accomplice, the enabler of hate.
Let me give an example of how hatred and indifference work together. She convinces herself that God has called her to end the life of the abortion provider. The people around her do nothing to stop her, nothing to move her away from her hatred. They have become her accomplices in the murder. Hate filled people are made possible by indifferent people.