Growing a Kingdom Heart
Matthew 5:21-48
Sermon on the Mount Series ・1・2・3・4・Part 5
There is a famous saying: “Show me who your friends are and I will tell you who you are.” The underlying principle is that the people we hang out with will influence who we become. I believe it’s true. We rub off on one another. For example, I have a friend who calls me “buddy.” I have never before in my life called someone by that term; but after several years of hanging out with this friend, I now freely use the word “buddy” in our text conversations. It wasn’t an intentional choice. It just happened. We become like the people we spend time around.
I think that’s why it’s such a grace that Jesus came and lived among us. He wanted to show us the best way to live, the way to flourish as human beings, and he did it by coming and hanging out with us.
That’s why when we read the Sermon on the Mount, it’s best for us to imagine ourselves there with him. We watch what he does. We listen to what he says. We try to discern why he is saying it. And most important, we open ourselves up to let who he is rub off on us.
As we talked about in the last post, righteousness is the key to Jesus’ message in his Sermon. This righteousness is a whole-person way of being in the world that conforms to God’s will. It’s not just about doing the right things; it’s about having the right heart. Here, in the body of the Sermon, Jesus is going to help us see what that heart looks like. And he begins by quoting six Old Testament Scriptures (“You have heard that it was said…”) followed by his own interpretation and application (“But I tell you…”).
“You have heard that it was said to the people long ago, ‘You shall not murder, and anyone who murders will be subject to judgment.’ But I tell you that anyone who is angry with a brother or sister will be subject to judgment… Therefore, if you are offering your gift at the altar and there remember that your brother or sister has something against you, leave your gift there in front of the altar. First go and be reconciled to them; then come and offer your gift.” (5:21-24)
Sure, it’s always the right decision not to murder someone, but having a Kingdom heart is so much more than that! The Kingdom heart recognizes the value in every human being as a person created in the image of God. The Kingdom heart refuses to let anger thrive or contempt reign. The Kingdom heart seeks reconciliation when relationships have been injured or broken.
“You have heard that it was said, ‘You shall not commit adultery.’ But I tell you that anyone who looks at a woman lustfully has already committed adultery with her in his heart.” (5:27-28)
Of course the act of adultery is always wrong, but the Kingdom heart has a much higher aim. The Kingdom heart places the right constraints on desire by refusing to nurture impure thoughts or objectify fellow human beings.
“It has been said, ‘Anyone who divorces his wife must give her a certificate of divorce.’ But I tell you that anyone who divorces his wife, except for sexual immorality, makes her the victim of adultery, and anyone who marries a divorced woman commits adultery.” (5:31-32)
Yes, Moses set up a process for divorce to address broken marriages, but that was meant to be an exception, not the rule (see Matthew 19:1-12). I believe what Jesus is doing in this example is standing up for women who were being easily discarded and left destitute by men who felt it was their prerogative to divorce their wives whenever they wanted to by simply filling out a certificate of divorce. The Kingdom heart takes the marriage covenant much more seriously than that and does everything possible to honor it.
“Again, you have heard that it was said to the people long ago, ‘Do not break your oath, but fulfill to the Lord the vows you have made.’ But I tell you, do not swear an oath at all…” (5:33-34a)
Swearing an oath implies there are times when your words can’t be trusted. The Kingdom heart is full of integrity, committed to the truth. A person with a Kingdom heart says what she means and does what she says. That person has no need for oaths.
“You have heard that it was said, ‘Eye for eye, and tooth for tooth.’ But I tell you, do not resist an evil person. If anyone slaps you on the right cheek, turn to them the other cheek also.” (5:38-39)
Vengeance is the way of the world. The Kingdom heart isn’t after retaliation. It trusts God to be the one to set things right. Instead, a person with a Kingdom heart is ready to respond with a surprising act of grace.
“You have heard that it was said, ‘Love your neighbor and hate your enemy.’ But I tell you, love your enemies and pray for those who persecute you…” (5:43-44)
Hating your enemies can feel natural. The people Jesus is speaking with had long been oppressed by the Roman government. As theologian Jonathan T. Pennington notes, hating their enemies might even have felt “divinely patriotic.” But Jesus calls Kingdom people to a higher standard. The Kingdom heart chooses to love everyone, even enemies.
The “greater righteousness” (5:20) Jesus calls us to is a whole-person way of being in the world that conforms to God’s will. It’s not just about doing the right things; it’s about having the right heart…a Kingdom heart.
Jesus concludes this section by calling us to “be perfect, therefore, as your heavenly Father is perfect.” (5:48) This isn’t meant to place an unrealistic expectation on us. It doesn’t mean we will never mess up. Rather, it is a call to wholeness. The Greek word teleios, which is often translated “perfect,” means complete, whole, mature. What it means to be “perfect” is to be whole, a Kingdom person inside and out.
So how do we grow this Kingdom kind of heart? We spend time with Jesus so that he rubs off on us. We let his words sink deep into our souls. We learn to think like him. We aim to love like him. We imitate his ways.
After all, Jesus is the wholly righteous one. Every thought, every motive, every word, every action of Jesus fully conformed to the Father’s will.
He is the reconciler.
Pure in motive, pure in love.
Faithful to the covenant.
His words are always true.
He did not retaliate when people attacked him.
And on the cross, he prayed for his enemies, “Father, forgive them.”
Jesus modeled what it looks like for a human being to live in the Kingdom of God. He is the embodiment of the Kingdom heart that he describes in this section.
Oh, that he would rub off on us. Oh, that he would rub off on me.
I want to be like Jesus. May he grow a Kingdom heart in me.
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Recommended Resources on The Sermon on the Mount
What If Jesus Was Serious? - Skye Jethani
Short reflections on the Sermon complete with Skye’s own doodles and drawings. This isn’t a deep dive into the Sermon, but it is an insightful and enjoyable read.
The Story of God Bible Commentary - Sermon on the Mount - Scot McKnight
A readable commentary by one of the most respected contemporary New Testament scholars. This commentary series not only explains the text, but provides insights on how to live out the Sermon in day-to-day life.
The Divine Conspiracy: Rediscovering Our Hidden Life in God - Dallas Willard
A theological work that is about more than the Sermon, but uses the Sermon as the key text to helping us live the life Jesus intends for us to live. This is not an easy read, but is a classic in Christian spiritual formation literature.
The Sermon on the Mount and Human Flourishing - Jonathan T. Pennington
A theological commentary that contains 130+ pages on overall themes of the Sermon before going into verse-by-verse commentary. I like how this author ties the Sermon into a vision for human flourishing.
