Is Self Defense Biblical?

Numbers 21:1-3
When the Canaanite king of Arad, who lived in the Negev, heard that Israel was coming along the road to Atharim, he attacked the Israelites and captured some of them. Then Israel made this vow to the Lord: “If you will deliver these people into our hands, we will totally destroy their cities.” The Lord listened to Israel’s plea and gave the Canaanites over to them. They completely destroyed them and their towns; so the place was named Hormah.”

     In the previous chapter the Israelites came to the border of Edom and asked permission to pass. They were denied with a soldiers guarantee. This may have made them appear weak. However, Moses was being diplomatic to them and good to his own people. However, those watching may have seen this as weak. 
     They continue traveling and are attacked by the canaanites and some of their people are taken captive. Moses and the people respond with strength. They destroyed their cities. This brings up the question of self defense. I think this has been greatly misunderstood. Matthew 5:39 is where much of that misunderstanding comes from, “But I say to you, do not resist an evil person; but whoever slaps you on your right cheek, turn the other to him also.” If we were slapped on our right cheek, that means we were hit with their left hand. That is not the power hand. This isn’t a beating, but a ritual. Much like in the victorian era, one would use a glove to slap. It’s done by someone who was outraged. Jesus calls this person evil and that we aren’t to participate. So, this person is faking outrage for some gain. Jesus is saying, let them play their game. Don’t stoop to their level. In fact, He’s saying to allow them to get it all out. Almost like “if you’ve been so hurt by me, slap my left cheek with you power hand. I didn’t mean to hurt you.” 

     In Luke 22:36 Jesus says, “But now, whoever has a money belt is to take it along, likewise also a bag, and whoever has no sword is to sell his coat and buy one.” He also tells them to get a weapon later on. This is the sword that Peter used in the garden. It sounds odd to know that Jesus is telling them to be armed. It was mainly for when they would travel the highways which were dangerous. But I’m sure it was for protection at any time. 
     If someone breaks into our house, we have a right to defend ourselves and our family. We aren’t to allow those we are responsible for to be abused. That’s what Moses and the Israelites did. They punished the agressors.
     This is a little uncomfortable. Most of us aren’t violent or agressive people. To be in a situation that required the use of force isn’t part of our daily lives. Usually law breakers are ready to be violent.  That’s why Jesus said to have a weapon. It gives an advantage. In today’s world it would be a firearm. 
     Lord, help us to protect our loved ones. I pray that it would never be necessary.