2CO 4:8-11 “We are hard pressed on every side, but not crushed; perplexed, but not in despair; persecuted, but not abandoned; struck down, but not destroyed. We always carry around in our body the death of Jesus, so that the life of Jesus may also be revealed in our body. For we who are alive are always being given over to death for Jesus’ sake, so that his life may be revealed in our mortal body.”
AC 4:23ff (condensed) “On their release, Peter and John went back to their own people and they raised their voices together in prayer to God. ‘Lord, consider their threats and enable your servants to speak your word with great boldness. Stretch out your hand to heal …’ After they prayed, the place where they were meeting was shaken. And they were all filled with the Holy Spirit and spoke the word of God boldly.”
The response to physical threats seems to be prayer and bold proclamation of God’s word, and prayer for miracles of healing (!), not taking up arms in self-defense. There is only one place in the New Testament where a follower of Jesus took up a weapon in self-defense, and he was stopped by Jesus (Mt. 26:52).
There were instances where Peter and Paul inflicted punishments (Acts 5:1-11, 13:11), but these were not in self-defense.
It seems that in Scripture when weapons are used, they are used in judgement (1 Sam. 15:2-3,33; Is. 34:6-8, etc.), though Est. 9:15 is an exception to this. But the self-defense in Esther is the result of a miracle of God, and the people did not arm and defend themselves before the decree was issued instructing them to do so, and Esther risked her life to approach the king and ask for this deliverance. So even this is clearly not teaching “if you are attacked, then arm and defend yourself”:
EST 4:1 “When Mordecai learned of all that had been done, he tore his clothes, put on sackcloth and ashes, and went out into the city, wailing loudly and bitterly.”
Jesus gave a clear command as the rule for how to respond to personal attack:
MT 5:39 “But I tell you, Do not resist an evil person. If someone strikes you on the right cheek, turn to him the other also.”
And though he made a whip of cords, he also used this only in judgment, and not in self-defense.
He taught the way of the cross, “for all who draw the sword will die by the sword.” When Jesus said to buy a sword, he may well have meant the sword of the Spirit, a copy of the word of God, for when he was told they had two metal swords, he responded “That is enough” (Luke 22:38).
“For the wont of the old law was to avenge itself by the vengeance of the glaive, and to pluck out ‘eye for eye,’ and to inflict retaliatory revenge for injury. But the new law’s wont was to point to clemency, and to convert to tranquility the pristine ferocity of ‘glaives’ and ‘lances,’ and to remodel the pristine execution of ‘war’ upon the rivals and foes of the law into the pacific actions of ‘ploughing’ and ’tilling’ the land. Therefore as we have shown above that the coming cessation of the old law and of the carnal circumcision was declared, so, too, the observance of the new law and the spiritual circumcision has shone out into the voluntary obediences of peace.” – Tertullian (c. 198-220)
“We have learned not only not to return blow for blow, nor to go to law with those who plunder and rob us, but to those who smite us on the one side of the face to offer the other side also, and to those who take away our coat to give likewise our cloak.” – Athenagoras (c. 180)