Matthew 5:46, nasb
As Christians living in a non-Christian world, we are faced with a tough decision: Shall we live by the law of the jungle, treating other people as we are treated, or shall we choose to live as God intends, making a choice as to how we live and treat others? The fact is most people respond to others with an "eye for an eye" and a "tooth for a tooth" mentality.
This means when people treat you nicely, you respond with the same, but when they treat you rudely or harshly, you respond with a dose of their own medicine.
God has always wanted His children to live and treat others differently than they are treated. The tendency to take an "eye for an eye" and a "tooth for a tooth" is as old as humanity itself. Bitterness–grudges, cataloging of grievances, awaiting the day to pay back your enemies–goes clear back to the Garden of Eden. But Jesus taught that His followers are to meet harshness with kindness, stinginess with generosity, and hatred with love.
Have you forgotten how He chided His disciples? In his Bible paraphrase The Message, Eugene Peterson puts it like this: "Here’s another old saying that deserves a second look: ‘Eye for eye, tooth for tooth.’ Is that going to get us anywhere? Here’s what I propose: ‘Don’t hit back at all.’ If someone strikes you, stand there and take it. If someone drags you into court and sues for the shirt off your back, giftwrap your best coat and make a present of it. And if someone takes unfair advantage of you, use the occasion to practice the servant life. No more tit-for-tat stuff. Live generously.
"You’re familiar with the old written law, ‘Love your friend,’ and its unwritten companion, ‘Hate your enemy.’ I’m challenging that. I’m telling you to love your enemies. Let them bring out the best in you, not the worst. When someone gives you a hard time, respond with the energies of prayer, for then you are working out of your true selves, your God-created selves. This is what God does. He gives His best–the sun to warm and the rain to nourish–to everyone, regardless: the good and bad, the nice and nasty. If all you do is love the lovable, do you expect a bonus? Anybody can do that. If you simply say hello to those who greet you, do you expect a medal? Any run-of-the-mill sinner does that.
"In a word, what I’m saying is, grow up. You’re kingdom subjects. Now live like it. Live out your God-created identity. Live generously and graciously toward others, the way God lives toward you" (Matthew 5:38-48, The Message).
The next time someone treats you rudely, ask yourself, "Do I choose to lower myself to the level of this person, or do I rather choose to treat him the way I believe God wants me to?" Resource Reading: Matthew 5:38-48