I learned a long time ago that the better you treat people, the better results you will get, even if it's their job anyway. If you call waitresses by their names and spend a little time noticing something about them—complimenting a pretty pin or expressing concern about a slight limp—you will get far better service. If you need to call a company, if you remember the name of the one who answers the phone and use it a few times, then tell them how much you appreciate the help they give you, even if it isn't all that much, the next time you have to call, they will remember and try harder to help you out. Once you establish that rapport, they will even do their best to help you with a complaint. Nine times out of ten, the better you treat people, the better they will treat you.
That should not be the way it is for a Christian. For a Christian, the worse people treat you, the better you should treat them. What?! Why that's just plain un-American, isn't it? Unfortunately it just might be, but "American" should not be your first descriptor to anyone. Maybe we should spend a little time on this.
We run around talking about agape love all the time like we actually know what it means, and then turn around and do the opposite. Look at Romans 5 and let the Lord show us how we are supposed to love.
For while we were still weak, at the right time Christ died for the ungodly. For one will scarcely die for a righteous person—though perhaps for a good person one would dare even to die— but God shows his love for us in that while we were still sinners, Christ died for us. Since, therefore, we have now been justified by his blood, much more shall we be saved by him from the wrath of God. For if while we were enemies we were reconciled to God by the death of his Son, much more, now that we are reconciled, shall we be saved by his life. (Rom 5:6-10)
Did you catch that? How were we treating God when he sent our Savior? We were weak, we were sinners, we were his enemies, and still Christ died for us. If you think that doesn't apply to us, let me remind you: For to this you have been called, because Christ also suffered for you, leaving you an example, so that you might follow in his steps. (1Pet 2:21)
Still not convinced? Let's try this: The fruit of the Spirit includes kindness (Gal 5:22), a word associated with God in such passages as, And has raised us up together, and made us sit together in heavenly places in Christ Jesus: That in the ages to come he might show the exceeding riches of his grace in his kindness toward us through Christ Jesus. For by grace are you saved through faith… (Eph 2:6-8). Here Paul makes it plain that the kindness of God is associated with his grace, meaning we did not earn it. That's the same word as the fruit of the Spirit "kindness." We are to be kind to others, not because they have been kind to us, but because God has been kind to us. And that's why we should always treat others better than they deserve.
And that puts me in mind of this: For with the judgment you pronounce you will be judged, and with the measure you use it will be measured to you. (Matt 7:2) If ever there was a time you don't want to get what you give, I think it might be this one.
Put on then, as God's chosen ones, holy and beloved, compassionate hearts, kindness, humility, meekness, and patience, bearing with one another and, if one has a complaint against another, forgiving each other; as the Lord has forgiven you, so you also must forgive. (Col 3:12-13)