The death toll from the mosque shootings in Christchurch, New Zealand, reached 50, it was reported Saturday. The 50 are Muslims, all slaughtered as they prayed at their place of worship. The suspected attacker, Brenton Harrison Tarrant, an Australian man, issued a manifesto of hatred toward Muslim immigrants online, and used a camera mounted to his helmet to broadcast live video of his attack, complete with his narration of the killing as he committed them.

The hatred that fueled this attack is something we have seen and tried to deal with in America. But it is nothing new. This hatred of others who are different from us goes back centuries, almost to the roots of human civilization. It can be based on religious differences, ethnic differences, sometimes simply geographical differences.

Tarrant’s manifesto said he is a white supremacist who wanted to avenge killings committed by Muslim terrorists in Europe. Revenge is an empty motivation, leading only to more violence, most likely against innocent people who pose no threat to the vengeful.

How do you deal with such murderous, insane hatred?

The vast majority of people in New Zealand are responding by supporting their Muslim neighbors, volunteering to help them however they can and doing acts of kindness.

Love is a wonderful reaction to hatred, but being aware of growing hatred and recognition of the threat it imposes is another. Groups that fan the flames of hatred and exploit it should be called out and investigated before they and their followers can act out with violence and murder.