In American society, the heart usually means our emotions. Biblically, the term is much richer. Elyse Fitzpatrick’s book Idols of the Heart: Learning to Long for God Alone shows that the heart consists of our mind (thoughts, beliefs, understandings, memories, judgments, conscience, and discernment), affections (longings, desires, feelings, imaginations, and emotions), and will (the part of us that chooses what actions we take). Thus the heart is the inner person. The will is especially important when studying forgiveness from the heart. Consider the Parable of the Unforgiving Servant in Matthew 18:21-35.
Then Peter came and said to Him (Jesus), “Lord, how often shall my brother sin against me and I forgive him? Up to seven times?”
Jesus said to him, “I do not say to you, up to seven times, but up to seventy times seven.
“For this reason the kingdom of heaven may be compared to a king who wished to settle accounts with his slaves. When he had begun to settle them, one who owed him ten thousand talents (billions of dollars) was brought to him. But since he did not have the means to repay, his lord commanded him to be sold, along with his wife and children and all that he had, and repayment to be made. So the slave fell to the ground and prostrated himself before him, saying, ‘Have patience with me and I will repay you everything.’ And the lord of that slave felt compassion and released him and forgave him the debt. But that slave went out and found one of his fellow slaves who owed him a hundred denarii (days’ wages); and he seized him and began to choke him, saying, ‘Pay back what you owe.’ So his fellow slave fell to the ground and began to plead with him, saying, ‘Have patience with me and I will repay you.’ But he was unwilling and went and threw him in prison until he should pay back what was owed. So when his fellow slaves saw what had happened, they were deeply grieved and came and reported to their lord all that had happened. Then summoning him, his lord said to him, ‘You wicked slave, I forgave you all that debt because you pleaded with me. Should you not also have had mercy on your fellow slave, in the same way that I had mercy on you?’ And his lord, moved with anger, handed him over to the torturers until he should repay all that was owed him.
“My heavenly Father will also do the same to you, if each of you does not forgive his brother from your heart.” (NASB-95)From this parable, we see that forgiveness always costs the forgiver. Forgiving us cost Jesus His life! Click To Tweet 
From this parable, we see that forgiveness always costs the forgiver. Forgiving us cost Jesus His life! Likewise, in God’s economy, unforgiveness always costs the un-forgiver (Matthew 6:15).
Then what does biblical forgiveness look like? Jay Adams in the Christian Counselor’s Manual states that if I forgive you, I am making three promises.
1. I promise not to bring the matter up again to use against you. God’s example is that He remembers our sin no more (Jeremiah 31:34; Hebrews 8:12, 10:17). He does not forget, but He chooses not to call the sin to mind.
2. I promise not to bring up the matter to anyone else against you. This is a promise not to commit the sin of gossip (Romans 1:29; 1 Timothy 5:13).
3. I promise not to dwell on the matter. When we keep turning something painful over in our minds, we are likely to become bitter, which is sin (Ephesians 4:31).
Each of these promises is a matter of the will, not emotions. We choose them to please and glorify God (1 Corinthians 10:31), to obey God because in Christ He has forgiven us (Ephesians 4:31-32), and to bless the one forgiven. However, these promises do not address the powerful emotions we may feel that scream against forgiving. Simply telling ourselves, “Don’t feel that way!” will not help. Instead, since reaching full forgiveness can be a process, we add two more promises.
4. When the feelings of pain come to mind, I promise to act as if I have forgiven (because I have), to remind myself of the first three promises, and then to redirect my thinking according to Philippians 4:8, i.e., to what is true, right, noble, pure, etc.
5. I promise to treat you as if the sin never happened. (Such kindness does not preclude possible consequences, e.g., an abusive spouse going to jail for crimes committed, or a child forfeiting a desired opportunity. Forgiveness implies commitment to pursue reconciliation to the extent possible. Reconciliation requires that forgiveness occurs first.)
By these two promises, I acknowledge that the pain is real and I reaffirm the first three promises. At first, this can be very difficult, but by making it a habit, in time my emotions will let go of the pain, anger, and other negative feelings that attended the situation. Later, I may even “forget.”
When should we forgive? Twice, the passage shows expressing forgiveness upon the other person’s confession or promise to make up for the matter. What if the other person refuses to confess, or cannot? In such a case, do we fail to forgive? No, in light of Matthew 6:15, we should not hold back. God does give us some options.
• If we can overlook a sin so that it does not keep coming to mind (Proverbs 19:11), we can simply forgive it as a private transaction with God. But if the other keeps repeating the offense, we need to address it for the sake of the other’s sanctification.
• If it is a deeper wound, we may still be limited to the private transaction. Suppose, for example, that the person has died?
• Before we address the situation, we must first take the log out of our own eye (Matthew 7:1-5), confessing our own sins. If the offender is available, we gently address the matter privately (Matthew 18:15). A helpful opening would describe the situation and ask if we did something to cause offense leading to the other’s action. If an unbeliever rejects the approach, we may have to drop it. With a believer in Christ, Matthew 18:15-20 applies.
• Between spouses, the husband should be first to humble himself, confess, and ask forgiveness, for he is to model godly leadership for his wife, including confession of sin (Ephesians 5:25; Luke 9:23). If he refuses, his wife should take the initiative in obedience to Christ. Perhaps the Spirit will use her obedience to motivate him. (But beware, abusers usually interpret such initiative as weakness and as license to continue abusing. Dealing with abuse is a separate topic.)
• If I am the recipient of this approach, I must take it seriously and not brush it off or turn it against the other as his or her problem—how would that be like Christ? Nor may I demand that the other “get over it,” a self-serving response, but repent.
Suppose someone sins, confesses, repents, receives forgiveness, and keeps repeating the pattern. If we raise the issue, are we violating the first promise? Not if we aim to help that one replace the sinful habit with a godly one (Ephesians 4:22-24). We could open with, “I am concerned about a pattern in your life and where it is leading.” Be prepared for resistance and calmly state that you want to help.
The promises are profound, costly, and NOT optional. “Forgive us our debts (sins) as we also have forgiven our debtors” (Matthew 6:12). If we refuse to forgive, what have we prayed against ourselves?
Is this kind of forgiveness too difficult? If so, then we realize that genuine forgiveness from the heart is both an act of the will and supernatural. If not, we have probably been practicing biblical forgiveness for some time. In either case, we all need the Holy Spirit’s help to live out God’s kind of forgiveness toward others. If we ask, He will be pleased to help us do it.If we willingly practice forgiveness from the heart in the little things, including gently addressing matters with offenders, we will please God and grow more like Christ. Click To Tweet 
If we willingly practice forgiveness from the heart in the little things, including gently addressing matters with offenders, we will please God and grow more like Christ. In addition, God will strengthen our “forgiveness muscle” for greater potential tests. Our graciousness may even avert some possible trials—God alone knows. Further, God will equip us through our faithful obedience to help others through their trials calling for forgiveness (1 Corinthians 1:3-4). Let’s all choose to forgive biblically!
This blog is adapted from a biblical counseling homework assignment “Forgiveness from the Heart,” © 2013, 2020 by Robert Kagels. If you would like a copy to use in your biblical counseling ministry, you may email me at email@example.com.