Put your sword back into its place; for all those who take up the sword shall perish by the sword. (Matt. 26:52)
If anyone is destined for captivity, to captivity he goes; if anyone kills with the sword, with the sword he must be killed. Here is the perseverance and the faith of the saints. (Rev. 13:10)
Never pay back evil for evil to anyone. Respect what is right in the sight of all men. If possible, so far as it depends on you, be at peace with all men. Never take your own revenge, beloved, but leave room for the wrath of God, for it is written, "VENGEANCE IS MINE, I WILL REPAY," says the Lord. "BUT IF YOUR ENEMY IS HUNGRY, FEED HIM, AND IF HE IS THIRSTY, GIVE HIM A DRINK; FOR IN SO DOING YOU WILL HEAP BURNING COALS ON HIS HEAD." Do not be overcome by evil, but overcome evil with good.
But I say to you who hear, love your enemies, do good to those who hate you, bless those who curse you, pray for those who mistreat you. Whoever hits you on the cheek, offer him the other also; and whoever takes away your coat, do not withhold your shirt from him either. Give to everyone who asks of you, and whoever takes away what is yours, do not demand it back. Treat others the same way you want them to treat you. If you love those who love you, what credit is that to you? For even sinners love those who love them. If you do good to those who do good to you, what credit is that to you? For even sinners do the same. If you lend to those from whom you expect to receive, what credit is that to you? Even sinners lend to sinners in order to receive back the same amount. But love your enemies, and do good, and lend, expecting nothing in return; and your reward will be great, and you will be sons of the Most High; for He Himself is kind to ungrateful and evil men. Be merciful, just as your Father is merciful.
For this is the message which you have heard from the beginning, that we should love one another; not as Cain, who was of the evil one and slew his brother. And for what reason did he slay him? Because his deeds were evil, and his brother's were righteous. Do not be surprised, brethren, if the world hates you. We know that we have passed out of death into life, because we love the brethren. He who does not love abides in death.
Though we walk in the flesh, we do not war according to the flesh, for the weapons of our warfare are not of the flesh, but divinely powerful for the destruction of fortresses.
(2 Cor. 10:3-4)
Jesus answered, "My kingdom is not of this world. If My kingdom were of this world, then My servants would be fighting so that I would not be handed over to the Jews; but as it is, My kingdom is not of this realm." (John 18:36)
Our struggle is not against flesh and blood, but against the rulers, against the powers, against the world forces of this darkness, against the spiritual forces of wickedness in the heavenly places. (Eph. 6:12)
These verses teach us the following:
1. The one who has faith in God does not take up the sword (the ancient equivalent of a gun) to defend oneself, because to destroy with a weapon fates one to be destroyed violently-- it perpetuates the cycle of violence, instead of shalom which is the kingdom of God.
2. The principle of God's kingdom is to love everyone, without exception, even those who do you or the ones you love harm. Jesus was Peter's first love, but Jesus said it wasn't appropriate to defend him with the sword.
3. To love everyone without exception means to harm no one. Jesus makes harming/killing the opposite of doing good (Mark 3:4). The child of God is to do good at all times, never to harm. To do evil is to be evil. To harm an evildoer is to be an evildoer.
4. The child of God is supposed to have exceptional love, not the normal everyday love. To love and to consider the well-being of the one who harms you is the distinction of the child of God. To only love those who consider your well-being is the way all people act, good or evil.
5. It is a distinction of God's kingdom that the only one who acts in defense of the Kingdom is God himself. God takes vengeance, God does harm, God defends. The child of God is to depend upon God alone for his defense, and not take it up himself.
6. The child of God is a soldier: a soldier in the spiritual realm. The child of God fights an enemy: Satan and his forces. The child of God wields weapons: weapons of the spirit. The citizen of God's kingdom is not to take up weapons of this world, nor to fight in wars of this world, but to act powerfully in the spirit world.