It is the idea that when I scratch your back, I expect that you return the favor. Jesus too counseled that we do unto others what we expect them to do for us (Matthew 7:12). He also encouraged his followers to make friends with mammon, in case they encounter hardships (Luke 16:9). Jesus, Himself, shall make use of the rule when He shall reciprocate with those that confessed and denied Him during their lifetime (Matthew 10:32-33). Jesus also applied the same reciprocation to forgiveness and the treatment of others (Matthew 6:15; 7:2). If we expect kindness come our way, then let us steer it by doing something nice to someone.
There is another side to reciprocation. Jesus also endorsed this kind. He asked His disciples, “If you love those that love you back, what reward will you receive? And if you greet only those that you know shall return your greeting, what more do you do than strangers?” (Matthew 5:46-47). The reference concerned the disciples’ behavior towards hostiles. Wit regard to the poor, the left hand was not to be cognizant of the deeds of the right hand (Matthew 6:3). For our society, this kind of reciprocation poses difficulties. We have to render to Caesar certification for the rewards we expect in heaven Matthew 6:4). There is great anticipation among Christians to be rewarded for their charitable efforts. We ought to guard against qualifying ourselves.
There is a third kind of reciprocation that Jesus liked more than any of the others. It is unexpected reciprocation. It goes to those that are unaware that they were serving Christ (Matthew 25:37-39). In helping a stranger, they did not know that they were obeying the Second to the Greatest Commandments (Luke 10:25-37). It was a Roman officer Jesus praised for his faith and concluded that surprised and unexpected strangers shall sit at his table with Abraham, Isaac and Jacob, but those that were so dead sure of a place in the future world of bliss shall not even be permitted to look in from the outside (Matthew 8:5-12). Like the five foolish virgins, too many Christians take too many things for granted (Matthew 25:1-13). We need to ponder these words, “Who then is that faithful and wise steward, whom his Lord shall make master over his household, to give the servants their portion of food when they need it? Blessed is that steward, whom his Lord when he returns finds doing his duty. You can be sure what I tell you, he will put him in charge over all his holdings” (Matthew 24:45-47).