This verse presents two different situations. In the first Christ’s disciple has received a request for help from someone whose need is genuine, presumably either because they are poor, or because they have faced some unexpected call on their resources which they are unable to supply (Luke 11:5-6).
This seems very surprising. Is the believer to aid and abet the cause of those who do evil in the world and to help them get away with it? Is he not to report crime committed against himself? Is he to make no effort to retrieve stolen goods? Does that not contribute to the breakdown of law and order and justice in the world? Human justice is one of God’s means of restraining evil in the world, and he has appointed governments for this very purpose (Romans 13:4). Government must operate in the world, and Christ expects it to do so (Matthew 5:25). When Christ tells his disciples not to resist evil, he does not mean them to encourage the breakdown of society. The law is still there, and the believer is entitled to use it to defend his rights. What he teaches here is that there should be an absence of revenge, and any spirit of pride that quickly grows angry at the infringement of personal rights. Our goods are given to us by God, and we are thankful for what we have received, but his commands are higher than our right to possess, and both in the case of those who have genuine need and in the case of those who would unlawfully take from us, we are content.
Why should we not resist evil? What good comes from doing so? There is good to us, for by not resisting those who would take from us we prove that we value obedience to Christ and our testimony more highly than our possessions. We avoid being provoked into the same evil that we see in them, and so avoid much sin. We do not respond to unreasonable behaviour with unreasonable behaviour of our own. Anger, violence, or revenge would be unreasonable behaviour. There are times when force is to be used: the state is entitled to use the sword for God had given it to maintain order in a nation. But in private interactions, we are not to return evil for evil. This is part of our testimony, and hopefully our testimony will have a good effect on those who observe it. This reasonableness is so contrary to what he expects and deserves, and he knows that perfectly well. This points to something in the believer that he does not understand, and will reflect deeply on (1 Peter 3:15). They see something in the believer which they know they are not capable of. This response comes from faith. The unbeliever can in reality take nothing of any value from us. He can only deprive us of this world’s good, but he cannot touch our inheritance in heaven. God preserves that for us out of the reach of the wicked.