Violence is a tool. It is not a hammer or screwdriver that goes in your toolbox for everyday use. It is a tool of last resort. It is behind the glass broken only in extreme circumstances. What are the appropriate circumstances? We always want to avoid violence but there are circumstances when violence is necessary.
The Qur'an and hadiths of Islam teach that violence is an appropriate tool for the propagation of religion.
Qur'an 9:5 - "So when the sacred months have passed away, then slay the idolaters wherever you find them, and take them captive and besiege them and lie in wait for them in every ambush, then if they repent and keep up prayer and pay the poor-rate, leave their way free to them."
Bukhari (8:387) - Allah's Apostle said, "I have been ordered to fight the people till they say: 'None has the right to be worshipped but Allah'. And if they say so, pray like our prayers, face our Qibla and slaughter as we slaughter, then their blood and property will be sacred to us and we will not interfere with them except legally."
Muslim (31:5917) - "Ali went a bit and then halted and did not look about and then said in a loud voice: 'Allah's Messenger, on what issue should I fight with the people?' Thereupon he (the Prophet) said: 'Fight with them until they bear testimony to the fact that there is no god but Allah and Muhammad is his Messenger'."
We can see from this last passage that Ali was sent to fight. It appears that he was not aware of any reason to be fighting. Muhammed gave him the reason – to make Muslims.
In contrast, The Old Testament does not contain any acts of violence for the purpose of propagating the faith to foreigners. Proselytizing did occur as Israel was to be “a light to the nations” (Isaiah 49:6) but violence was not the tool for this task. The Hebrew conquest of Canaan was a period in which God-ordained violence occurred but the purpose of the conquest was not to gain converts. Later, Jesus and the entire New Testament make it very clear that violence must never be a tool for the Church to spread Christianity or the gospel message. Paul reasoned with the philosophers at Mars Hill, but he didn’t have them killed for their disbelief.
This brings us to the question of self-defense. When Jesus was being arrested, Peter jumped out and tried to defend him with his sword. ...“Put your sword back into its place. For all who take the sword will perish by the sword.” (Matthew 26:52) was Jesus’s reply.
What is the sword’s place?
What is the rightful place of the sword? It was common in Ancient Rome to carry a sword, and while the laws went back and forth, certain citizens were generally encouraged to protect themselves from theft. The right to defend yourself is hardly a modern concept.
We grant to all persons the unrestricted power to defend themselves (liberam resistendi cunctis tribuimus facultatem), so that it is proper to subject anyone, whether a private person or a soldier, who trespasses upon fields at night in search of plunder, or lays by busy roads plotting to assault passers-by, to immediate punishment in accordance with the authority granted to all (permissa cuicumque licentia dignus ilico supplicio subiugetur). Let him suffer the death which he threatened and incur that which he intended (Codex Justinianus (“CJ”) 3.27.1).
This was a cultural norm that Jesus had many opportunities to speak against with his disciples if that was his desire. Peter, who had been traveling with Jesus for 3 years was still wearing a sword. Jesus has not discouraged the defense of oneself, in fact, he told him to put it back in its place, not to discard it. The sword's place is self-defense and the protection of the weak. Its place is not in the advancement of the Kingdom. God has no interest in followers gained by the sword.
Jesus acknowledged the role of the sword in self-defense outright as he prepared his disciples to carry on after his crucifixion.
And he said to them, “When I sent you out with no moneybag or knapsack or sandals, did you lack anything?” They said, “Nothing.” He said to them, “But now let the one who has a moneybag take it, and likewise a knapsack. And let the one who has no sword sell his cloak and buy one. For I tell you that this Scripture must be fulfilled in me: ‘And he was numbered with the transgressors.’ For what is written about me has its fulfillment.” And they said, “Look, Lord, here are two swords.” And he said to them, “It is enough.” - Luke 22:35-38 ESV
Here, Jesus is pointing out that he took care of them during his earthly ministry, but he is going to the cross to be counted among the transgressors in fulfillment of prophecy. This is not a lesson on self-defense but simple 1st century Palestine packing instructions. You are going to need to pack a sword. Why? Because he would not be there to take care of you and I does not want you to get robbed and/or killed by robbers. A very clear acknowledgement that self-defense is sometimes necessary. Self-defense is a form of violence. It can be a justified violence. The sword also is a deterrent of violence and this is no small point but is perhaps off topic.
Besides self-defense, there is also a time for protecting the weak and the oppressed.
Give justice to the weak and the fatherless; maintain the right of the afflicted and the destitute. Rescue the weak and the needy; deliver them from the hand of the wicked.” - Psalms 82:3-4 ESV
Jesus himself, on one single occasion had to ‘break the glass’ and use the tool of violence. Money-lenders were using the area outside of the temple to take advantage of the poor by providing unfair conversions of currency in order to sell over-priced animals for sacrifices. (Matt 21:12-13) Jesus overturned the tables and drove them out. John adds that he made a whip out of cords in order to do so (John 2:13-22). This is certainly not prescriptive behavior for us but it reflects the zeal that Jesus had and his willingness to use an appropriate level of violence to protect those being oppressed by this monetary policy being orchestrated at the temple.
This incident perplexes us. We have assembled a safer view of Jesus that causes us to be slightly dissonant when we consider his purging of the Temple. Like Susan, from the Chronicles of Narnia when she learns that Aslan is a Lion and she is going to meet him. She says "Oh, is he safe?". Mr. Beaver exclaims "Safe? Who said anything about safe? Course he isn't safe, but he's good. He's the King, I tell you"
Paul, while providing a formula for how to best take care of widows that need the most help without placing a burden on the church for those that might not need help lays out a mandate for believers. He says “But if anyone does not provide for his relatives, and especially for members of his household, he has denied the faith and is worse than an unbeliever.” (1 Timothy 5:8) Here, Paul is not talking about self-defense. He is saying that a family is the first line of responsibility for the care of those of its members in need. He does not want the Church to be burdened with a familial responsibility. Certainly, protection, if necessary, is a matter of care for one’s family. I believe that this same concern for burdening the Church applies to the state. The state, in many circumstances, cannot provide safety and protection and this responsibility falls on the family.
Conclusion
Sometimes a right can be misunderstood and separated from its underlying responsibility. We get caught up on the idea of a ‘right’ and confuse it with a claim to some sort of privilege or entitlement. The right to self-defense is a responsibility to maintain a just society. If we collectively make it easier for criminals then it can inadvertently welcome more crime. In the case of a home invasion, we are commanded to love even the intruder but also love those in our home. Using the least amount of force and causing the least amount of harm to the intruder is how you do that. If you argue that you cannot love while restraining, harming, or even killing someone to prevent harm to others is to argue that there are those that God, in the Old Testament did not love. When you aggregate love to society, you get justice.
It is true that two people attacking each other could both be claiming self-defense. This abuse does not justify taking away the right altogether any more than the financial abuses of a televangelist takes away our right to preach. Jesus says as much when he instructs us to turn the other cheek. He is pointing to a better way (than retribution) but turning the other cheek is not the same as offering the throat of those under your care. It is a worthwhile conversation to discuss the circumstances under which we should not defend ourselves and forego our life and/or property for the sake of the gospel but it's clear from Scripture that the answer is not always.
I think most of us see the need for the right to defend ourselves and have the tools to protect others. If you want a police force then you are acknowledging the need to protect others from those who would steal from them or oppress them. Most want the police to have the ability to use deadly force, if necessary – and only when necessary. What you are doing here is outsourcing your right to self-defense. You could not give others the responsibility to carry out this task if it is not a right that you have. Am I my brother’s Keeper? Genesis 4 tells us that the answer is undoubtedly yes; both spiritually and physically which can include protection and defense.