In the Old Testament sure. In the New Testament, though you didn’t mention it, there’s also a part that says that there would be a time when the disciples should carry a sword. However, when Peter uses it on the soldier’s ear Jesus rebukes him and heals the guy’s ear. If not necessary, I think turning the other cheek is called for. We have “thou shall not kill” but that doesn’t really apply in war. In self-defense against some drugged-out person not in their right mind? Then ideally the person might get injured but sometimes they don’t stop and people have to act fast. Even police officers have had to shoot to kill. Unfortunate, but it happens. I don’t think giving them your cloak or stereo implies consent to rape. Jesus said to sell all your possessions to the rich person and where your treasure is there will your heart be also. Do not store up wealth but store your treasures in heaven. That’s all about material objects and money, not about people. If God hated when the parents sacrificed their sons and daughters to idols He would not advocate letting them get raped. And of course the guy would want to defend his mom. I’m not placing judgment here, just stating some suggestions from a different perspective. If it’s a junkie, then you would know where the money is and could potentially bribe them with the promise of more? It’d either get them out of your house quicker with what they want, or stall them enough while the cops arrive without hurting anybody. A sociopath that just wants to kill is probably rare. However, these are just suggestions.
Anybody can say what they might do, but you won’t know till you are in the situation yourself. That’s a scary incident, a home broken into in plain daylight with the people home. A sign like you mentioned might help in that they could be deterred if they believe the people inside own a gun. Not to go into the whole gun control issue, but I think in part that the fact that some people own them helps control crime a little because the only people that would give up their guns if the government took them are law-abiding citizens and the criminals would still be getting them the same “underground” ways they always have. Why would they turn them in and suddenly start following the law when they’ve been breaking it all this time? If a sign like that helps give you some peace of mind, I’d say go ahead and put it up. I just hope you never carry out what it would imply. Both for your sake and the sake of whoever might decide to ignore it. People shouldn’t be breaking into people’s homes, but they do. So I hope they catch whoever’s doing it in your neighborhood before somebody gets hurt.
I know it’s a work of fiction, but have you ever watched Les Miserables? The protagonist Jean Valjean initially stole some bread because he was hungry, then stole from the priest that helped him. However, instead of turning him back into the police where he would go to jail again, the priest gave him some candlesticks on top of that and said he could use the money from what he took to start a new life and turn it around. Even though the rest of the world would have treated him like a criminal, Jean Valjean was so touched that he did turn his life around, because the priest had such faith in him that he could do it. If you read David Wilkerson’s non-fiction book The Cross and the Switchblade, he helped bring many gang members to Christ. Ones that had killed and yet the Holy Spirit was able to turn their lives from evil to good.
We shouldn’t underestimate the power of prayer and God. The wisdom of God is foolishness to them that are perishing, but it is the power of God to those that are being saved (1 Corinthians 1:18). We know better, it’s the world that doesn’t recognize the truth which is why we ought to be sharing the gospel at every opportunity we get. This might involve even with those that might break into our home, though as you pointed out these are likely not gracious people. Yet, the following verses come to mind. “Whoever seeks to save his life will lose it, but whoever loses his life for My sake will find it” (Matthew 16:25). If you live by the sword you’ll die by the sword (Matthew 26:52). We have choices because we have free will, but bloodshed sounds like the last choice God would want. I’d say violence often begets violence. The people that break in might be just as scared and react violently if they see you are armed and you may not be the one their bullet hits. Use your own discretion in whatever the situation may call for, but be careful. “Behold, I am sending you out as sheep in the midst of wolves, so be wise as serpents and innocent as doves” (Matthew 10:16).