Jesus’ teaching to love our enemies was understandably shocking to his original audience—just as it is to us today. Jesus expected much, which is why, after telling his audience to love their enemies he added that if we only love those who love us and do good those who do good to us, we’re doing nothing more than what everyone naturally does (Luke 6:32-33). But his followers are to be set apart by the radically different way of love. The distinct mark of the reign of God is that God’s people love and do good to people who don’t love them and don’t treat them well—indeed, to people who hate them, mistreat them, and even threaten them and their loved ones.
To drive home the importance of this, Jesus says that if we love even our enemies, “then your reward will be great, and you will be children of the Most High, because he is kind to the ungrateful and wicked.” The parallel in Matthew has Jesus saying, “Love your enemies and pray for those who persecute you that you may be children of your Father in heaven. He causes his sun to rise on the evil and the good, and sends rain on the righteous and the unrighteous.”
Just as God is indiscriminately kind to the ungrateful and the wicked, and just as the Father causes the sun to shine and the rain to fall indiscriminately on the evil and the good, so followers of Jesus are to be distinguished by our ability to love indiscriminately. It makes no difference whether the person is friend or foe. And this, Jesus emphasizes, is the condition for our receiving a Kingdom reward and for our becoming “children of your Father in Heaven.” Our willingness to go against our nature and love and serve enemies rather than resort to violence against them is the telltale sign that we are participants in the Kingdom of God.
Notice that there are no exception clauses found anywhere in the New Testament’s teaching about loving and doing good to enemies. Indeed, Jesus’ emphasis on the indiscriminate nature of love rules out any possible exceptions. The sun doesn’t decide on whom it will and will not shine. The rain doesn’t decide on whom it will and will not fall. So too, Kingdom people are forbidden to decide who will and will not receive the love and good deeds we’re commanded to give.
(This is an excerpt from Myth of a Christian Religion, pages 99-100.)