Larger Thought Unit
The larger unit for this section is 6:12-49 which includes the ‘Sermon on the Plain’ as opposed to Matthew’s more famous ‘Sermon on the Mount.’ The above reading is a small section from this sermon. The key to understanding this entire section is knowing that it is written in the light of the ultimate kingdom of God as the true reference for discipleship, with the above passage condemning reciprocity as a guiding principle for behavior and replacing it with the unlimited generosity of God himself.
Notes
This is a classic example of the intimate connection between Luke-Acts and the Pauline literature, especially the letter to the Romans. This pericope is a compendium of the Pauline teaching.
The heart of the matter is the love of the neighbor, even the one whom we consider our enemy:
Let love be genuine; hate what is evil, hold fast to what is good; love one another with brotherly affection; outdo one another in showing honor… Repay no one evil for evil, but take thought for what is noble in the sight of all. If possible, so far as it depends upon you, live peaceably with all. Beloved, never avenge yourselves, but leave it to the wrath of God; for it is written, "Vengeance is mine, I will repay, says the Lord." No, "if your enemy is hungry, feed him; if he is thirsty, give him drink; for by so doing you will heap burning coals upon his head." Do not be overcome by evil, but overcome evil with good. (Rom 12:9-10, 17-21).
Moreover, notice Luke’s choice of words. “Sinners” is used of the Gentiles when compared to the Jews: “We ourselves, who are Jews by birth and not Gentile sinners.” (Gal 2:15). What appears as “credit” in the RSV is actually “grace” (χάρις) in Greek, meaning: the command to love the ‘outsiders’ is the teaching of the gospel of grace as we learn from Galatians: “I am astonished that you are so quickly deserting him who called you in the grace of Christ and turning to a different gospel” (1:6); “You are severed from Christ, you who would be justified by the law; you have fallen away from grace” (5:4).
If we are asked to behave thusly, it is because we ourselves are the recipients of this gospel of grace: “But God shows his love for us in that while we were yet sinners Christ died for us… 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 5:8, 10) God loved us first through Jesus Christ, and we are asked to follow suit by loving those whom we consider “sinners” and “enemies”: “… and the life I now live in the flesh I live by faith in the Son of God, who loved me and gave himself for me.” (Gal 2:20)
Hence the command: “Be merciful (οἰκτίρμονες), even as your Father is merciful (οἰκτίρμων).” (Lk 6:36) Compare with the following:
Blessed be the God and Father of our Lord Jesus Christ, the Father of mercies (οἰκτίρμων) and God of all comfort (2 Cor 1.3)
So if there is any encouragement in Christ, any incentive of love, any participation in the Spirit, any affection and sympathy (οἰκτιρμοί), complete my joy by being of the same mind, having the same love, being in full accord and of one mind. (Phil 2:1-2)
Put on then, as God's chosen ones, holy and beloved, compassion (οἰκτιρμοῦ/), kindness, lowliness, meekness, and patience, forbearing 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)
Further resource
Charles H. Talbert, Reading Luke, Smith & Helwys Publishing, Macon, GA, 2002; pp 71-79
Paul Nadim Tarazi, New Testament Introduction, Vol.2: Luke and Acts, St Vladimir’s Seminary Press, Crestwood, NY, 2001; p.61.