It's an important distinction especially when it comes to the heart of forgiveness. We are all familiar with the scenario: someone sins against you, it hurts for awhile, but after some time passes you think or say, "It's ok. I've forgiven them in my heart."
Done. Easy. Water under the bridge. They hurt you. Sin happened. But eventually you are able to muster up enough humility and selflessness to be able to come to the point of forgiving them in your heart. How noble your heartfelt actions are.
And how convenient.
No confrontation needed. No difficult conversation. No having to look someone you love in the eye and tell them that they hurt you—indeed sinned against you. No recognition needed on their part that sin has happened. No, it's all taken care of because you are willing to forgive them in your heart. It's so easy, in fact, that not a word needed to be uttered between the sinner and the sinned-against. Forgiveness has been successfully and seamlessly wrought.
In Matthew 18, Jesus teaches about true forgiveness. Too often this chapter is referred to using shorthand that means something like, "Take the steps of 'church discipline' outlined by Jesus to work reconciliation in Matthew 18:15-20." Is gossip happening at work? "Matthew 18." Is your friend complaining to you about an issue they have with someone else? "Matthew 18." Did so-and-so at church go behind your back and smear your reputation? "Matthew 18." This "Matthew 18" language isn't all bad. It's a good reminder that Jesus says, "If your brother sins against you, you go to him and tell him his fault, between you and him alone" (Matt. 18:15). Sin between people must be reconciled between those same people—and no one else.
What's often not asked, however, is why Jesus even gives these steps to take with our brother or sister who has wronged us. It's rather profound that he locates the "steps" in the larger context of who is the greatest in his reign/kingdom. All the way back in verse one, the disciples ask Jesus, "Who is the greatest in the kingdom of heaven?" And to answer their question, he takes a child, places him in the midst of them, and basically says, "This one and people like him are the greatest." That is to say, the neediest, lowliest, most dependent, most straying, utterly foolish, and terribly ignorant ones among you—they are the greatest. Jesus is not teaching about having an innocent, child-like faith. Rather, he's exhorting his disciples to turn—repent and become like children. This means to recognize their true position, which is lowly, humble, needy, unworthy, and completely dependent—regardless of how "great" they think they might be.
Jesus then warns them that these weak, lowly, dependent ones among them are so great that the person who would lead them into folly and sin is actually better off dead at the bottom of the ocean. He goes on to say hyperbolically that if your hand or foot or eye might tempt you to sin (and by correlation, might tempt these weak/great ones to sin), cut it off. Such is the sobering seriousness of sin. Then he uses the example of the single straying sheep. That straying, foolish sheep is so great that the shepherd leaves the 99 to go after it and rejoices when he finds it.
Then we get to the ever-popular "steps". Only after this whole teaching on greatness, then Jesus says, "If your brother sins against you, you go to him and show him his fault." Why does he say this? Because that one is the greatest.
...let me say that again.
That one is the greatest.
That's right. Contrary to every carnal, crusty, Old-Adam proclivity that dwells in the dark recesses of our hearts and minds; contrary to every self-justifying, self-defending argument that we can marshall to show ourselves to be in the right; contrary to every selfish attitude that pridefully waits around for them to come to you; the reality that Jesus proclaims is terrifyingly true: the one who sins against you is actually the greatest; the neediest; the straying one. They are the greatest, and need to be sought after and brought back into the fold. And how does that happen? By simply forgiving them in your heart? Not quite. Rather:
...from your heart...
...for your brother or sister in Christ to hear.
Jesus doesn't tell you to wait until you feel like forgiving your brother before you go to confront him. He doesn't ask you to psychoanalyze the situation to see if your neighbor is deserving of your forgiveness or if they will "really mean it" if and when they say, "I'm sorry." No, your sinning brother is the greatest. Period. And so you go to care for him.
And not only do you go because he is the greatest, but also because you have been so greatly forgiven by your Lord, as the parable of the unmerciful servant illustrates (Matt. 18:23-35). You go because your own great, unpayable debt of sin was forgiven by Jesus. Your Master didn't see your huge debt of sin and sit down with you to figure out a payment plan so that you could work it off (which, in the parable would amount to something in the ballpark of 200,000 years of labor). No, instead he graciously cancelled the whole thing altogether by his shed blood on the cross. And so you go to your brother bearing forgiveness, the source of which is not you, but Christ. You go to show your brother his fault so that you can forgive him, even as you have been greatly forgiven. And yes, the sobering warning is that if you refuse forgiveness to your repentant brother or sister, then you can expect the full debt of your sin to be reinstated by God. After all, to withhold forgiveness from your repentant neighbor—no matter how justified you may think you are to do so—is tantamount to despising the forgiveness given to you by Christ.
This is why we don't just forgive others in our hearts, but from our hearts—using words:
Person A: "You sinned against me."
Person B: "I'm sorry, please forgive me."
Person A: "I forgive you."
And when the words are spoken, the deed is done. It's simply how forgiveness is delivered. You don't have the luxury of forgiving your brother or sister wordlessly in your heart. And even if you do forgive them in your heart, how will your brother or sister know it? What good does it do to forgive them in your heart if you never tell them that? No, Jesus exhorts you to forgive your bother or sister from your heart, using words spoken to them.
Does that mean having some hard conversations? Indeed. Does it mean the potential for even more hurt feelings? To be sure. Does it mean that you might even have your own sin exposed to you by your bother or sister? Quite possibly. Does it mean that you have to forsake your self-justifying pride? Absolutely. But consider the even more difficult alternative: the greatest one among you might be left in his sin, maybe even unknowingly, maybe even to his eternal harm. Therefore, as the greatest, he requires your utmost care and attention.
You see, these are more than mere steps to follow in order to get something off of your chest to make yourself feel better, or to weed out the wicked from your midst. They are actually the way that we care for the greatest among us.
So go with words to speak to those brothers and sisters in Christ who have sinned against you. Go, not in haughty pride as if you have got it all together. But go as a fellow foolish one; a simultaneously sinful one. Go in humble concern in order to care for the greatest among you.
Oh, and pray for humility for the time when your brother or sister in Christ does the same to you, and give thanks to God that they loved you enough to do it.