There are many questions regarding repentance and how to know when a person has truly repented of sin.  Knowing this is crucial in helping a person who has been sinned against to begin to trust again and have any faith that the behavior won’t be repeated.

Has someone who sinned against you claimed to have repented of their sin? Biblically true repentance is a threefold response to sin that is found in the use of three different words that express a different aspect of repentance. All three components or aspects must be present for there to be fruit of true repentance in a person’s life.

The first response of repentance is found in the Greek word metanoeo which means a “change of mind” (Matt. 3:2, Mark 1:15).

When a person has a change of mind it means that he/she has acknowledged their sin.  This is what we find when a person confesses their sin. They admit and understand that what they have done is sinful. There is no justification or rationalization attached to the sin, no attempts to minimize or blame shift the responsibility for it onto someone else. There is personal guilt attached to the acts that have been committed.

Repentance cannot stop here because it is incomplete. There are plenty of situations where a person has confessed their sin and admitted their guilt and nothing more happens with them.  There is no other visible change and things go back to normal; meaning the sin resumes at some point or something else takes its place.

An excellent example of this would be the Pharaoh as he dealt with Moses and the Israelites.  Twice (Ex. 9:27; 10:16) he admitted to Moses, “I have sinned against the Lord your God.”  He admitted he sinned, he did not justify or rationalize or shift the blame and yet he did not repent.  There were no changes that accompanied his admission; in fact, he went right back to his behavior! King Saul had the same kind of limited repentance (1 Sam. 15:24, 24:17; 26:21) and he did not cease in pursuing David no matter how sorry he was. It is clear that just admitting sin does not equal repentance.

The second critical aspect of repentance is metanolomai (Matt. 21:29, 32; Heb. 7:21) and it means “change of heart.” In addition to admitting and confessing their sin thee must be a change of heart with respect to the sin; what they once loved and worshiped they now hate.

There is no longer room in his/her heart for the lust they sought to fulfill; in fact there is a growing hatred for everything that led him/her to commit the sin in the first place.  We could call this a holy hatred and it is an emotional response that is experienced in the body in the form of deep sorrow over their sin.

An important difference must be made here: there is a great difference between worldly sorrow and godly sorrow.  Godly sorrow has as its first concern the honor of God. It is other’s oriented and is produced by the Holy Spirit acting on the conscience of a sinner.  This kind of sorrow cries out, “Woe is me” and causes a person to weep bitterly over the sin he/she has committed.

When the Apostle Peter denied Christ three times after the arrest of Jesus he went off and wept (metanoeo). He was heartbroken over his sin and over how he had betrayed the One he loved.  By comparison Judas also repented (metamelomai), meaning he had a change of heart about betraying an innocent man he felt guilty about it and sought to rectify it by returning the money he was paid.  His hope was to erase his guilt and somehow undo what he had done. He then went and hung himself (Matt. 27:3-5).

It is important to note that repentance is a manifestation of the life of Christ in a person.  It is a proof of salvation in a person’s life. The sinner (Peter in the above example) has been cut deeply to the heart by the Spirit of God and or the Word of God that their sin is grievous to the Lord and because of that they no longer desire to participate in it.

Worldly sorrow is “unsanctified remorse”[i] (Judas in the above example) and is focused on feelings of regret, fear, and even desperation.  Its focus is on how the sin or its exposure will affect them. MacArthur further says that worldly sorrow “has no redemptive capability. It is nothing more than the wounded pride of getting caught in a sin and having one’s lusts go unfulfilled.”[ii]

The first two kinds of repentance take place in the inner man, or the heart. This is critical because as the heart is changed the actions change, which lead us to the third part of this critical aspect of change.
Finally, there must be metanoia which is a “change the course of life” (Matt. 3:8; 9:13; Acts 20:21).  We know that the Apostle Peter truly did repent because his life demonstrated all of the aspects of repentance: he understood his sin (fear), he grieved over his sin (fear of man) and his life changed (he boldly proclaimed Christ for the rest of his life, ultimately being martyred for the faith).

Changing the course of life involves an act of the will, a turning from the sinful behavior. There must be a radical amputation of the actions. In other words the sin is no longer taking place.  When the sin is a sexual sin of some kind, repentance means that the pornography has been disposed of, the Facebook account has been deleted, the email has been closed.  

"If your hand causes you to stumble, cut it off; it is better for you to enter life crippled, than, having your two hands, to go into hell, into the unquenchable fire,[where their worm does not die, and the fire is not quenched.] "If your foot causes you to stumble, cut it off ; it is better for you to enter life lame, than, having your two feet, to be cast into hell, [where their worm does not die, and the fire is not quenched.] "If your eye causes you to stumble, throw it out; it is better for you to enter the kingdom of God with one eye, than, having two eyes, to be cast into hell, Mark 9:43-47

When repentance is genuine you will see all of this and the change will be dramatic.
Repentance is not something a person can conjure up from within. No amount of screaming or threatening will force a person to repent.  Repentance is a gift from God.  Repentance can come quickly or sometimes will take years but one thing is for certain: a regenerated Christian will repent.  There is no way for a person to live long-term under the conviction and ministry of the Holy Spirit without repenting.

[i] John MacArthur Study Bible footnotes on 1 Corinthians 7:10
[ii] Ibid.