For he makes his sun rise on the evil and on the good, and sends rain on the just and on the unjust. For if you love those who love you, what reward do you have? Do not even the tax collectors do the same? And if you greet only your brothers, what more are you doing than others? Do not even the Gentiles do the same? You therefore must be perfect, as your heavenly Father is perfect.
(Matthew 5:45b-48, ESV)
This is some pointed preaching from Jesus. And preaching isn't meant to be read, but to be heard. So, slow down for a moment, and read these verses out loud, or have someone read them - better, proclaim them - to you. And think about what he is saying...
"Are you only loving the people who love you? What kind of reward do you think that will bring? And, take a look around at people who claim no allegiance to the Ruler of the universe - rebellious, lost, raising-their-fists-in-His-face sinners - do you see them acting any differently? You don't, because loving only people who love you is a pretty low standard to meet." (v. 46)
"Let's talk about your kindness-meter for a second. Are you kind only to your friends? What about strangers? What about your enemies? Is it only when people you know cross your path that a cheerful greeting passes your lips? Isn't that how pretty much everybody acts?" (v. 47)
Jesus knows people, knows them really well (John 2:24). And so he takes this moment in his sermon to ask some questions, express what he sees, and press in deep right where we need growth. Because Jesus knows that left to ourselves, we'll always set the standard too low. The standard isn't self-assigned, and it isn't determined by the people we hang with.
No, it is here that Jesus delivers the homiletical punch: We must be just like our Heavenly Father (v. 48). Specifically, we must be perfect, as he is perfect.
The word Jesus uses here is telos in the original. It means to be fully developed, full-grown, or mature in a moral sense. Jesus is teaching us that if we claim to be his followers, then what we are to emulate is the character and behavior of God himself as we relate to those around us. When we wonder how we should respond to or engage people, we look to the Father's example - found in the story of the Bible - and we act like him.
To which we respond, "Whoa - wait a minute! I know I may set the bar too low, but now, Jesus, you just went and set it way too high!"
That would be the wrong response. Just because Jesus sets this as the standard, doesn't mean he thinks we will prefectly attain this level of moral maturity and growth. The rest of the teaching of Jesus and the Apostles about confession and need of forgiveness makes that really clear (e.g., see 1 John 1:7-10).
No, the point here is that the perfection of the Father is what all disciples of Jesus pursue.
And that, my friends, gives us much to think about as we memorize this section of the Sermon on the Mount this week.