You have heard that it was said to the people long ago, 'Do not murder, and anyone who murders will be subject to judgment.' But I tell you that anyone who is angry with his brother will be subject to judgment. Again, anyone who says to his brother, 'Raca,' is answerable to the Sanhedrin. But anyone who says, 'You fool!' will be in danger of the fire of hell.
This is Evelyn De Morgan's The Red Cross, sometimes called A Christ of the Battlefield. She composed and exhibited this work in 1916 in reaction to the senseless, purposeless slaughter that was the First World War.
War and violence may be necessary. It may even be justified at times. But it always grieves God. The snuffing of a single life, even the most depraved among us, is the death of one of God's own dearly beloved children. The hand which strikes to preserve life and liberty must be stretched out, but it is always a tragedy.
We are permitted to be violence under some circumstances. But we are never permitted to hate. There is such a thing as Just War, but there is never Just Hate:
You have heard that it was said, 'Love your neighbor and hate your enemy.' But I tell you: Love your enemies and pray for those who persecute you, that you may be sons of your Father in heaven. He causes his sun to rise on the evil and the good, and sends rain on the righteous and the unrighteous. If you love those who love you, what reward will you get? Are not even the tax collectors doing that?
Sometimes I think about people who have greatly hurt me in the past. I may mourn for their actions, but I may never hate them. For how can I seek the mercy of God when I despise the children whom he loves? To hate is to murder, and to murder to slay a child of God, precious in His sight.
UPDATE: Sally Coleman has reflected on this painting, too.