Love your enemy

SB “My Kingdom is no part of this world. If my Kingdom were part of this world, my attendants would have fought that I should not be handed over to the Jews. But as it is, my Kingdom is not from this source.” ​—John 18:36.

Love your enemy is the third greatest commandment given by Jesus. Jesus told his followers: “Continue to love your enemies and to pray for those who persecute you, so that you may prove yourselves sons of your Father who is in the heavens.” (Matthew 5:44, 45)

War
In many conflicts, religious leaders on both sides claim that God is on their side. “Religion has always played a part in every war that was ever fought”—Causes of War by Jack S. Levy.

The Christian does well to follow Jesus' third to command to love their enemy, not fight against them. The apostle Paul wrote to fellow Christians: “If possible, as far as it depends on you, be peaceable with all men. Do not avenge yourselves.”​—Romans 12:18, 19. Even when the nation of the Christian goes to war, that one must remain neutral by having “no part of the world” (John 15:19) because there is a "judging of this world" and "the ruler of this world will be cast out" (John 12:31).