Repent -- among the very first words spoken by both John the Baptist and Jesus when they began their mission.

Matt. 3:1,2 John the Baptist, preaching in the wilderness of Judaea,
came saying, Repent ye: for the kingdom of heaven is at hand.

Matt. 4:17 Jesus began to preach, and to say, Repent: for the kingdom of heaven is at hand.
Mark 1:14-15 Jesus came into Galilee, preaching the gospel of the kingdom of God, And saying, The time is fulfilled, and the kingdom of God is at hand: repent ye, and believe the gospel.

Mark 6:7,12 And he called unto him the twelve, and began to send them forth by two and two; And they went out, and preached that men should repent.
Mark 13:2-6 Jesus answered them, ...except ye repent, ye shall all likewise perish. ..Do you think they were worse sinners than you... no, except ye repent, ye shall likewise perish.

Repent, is also what the apostles preached.

Acts 2:38 Then Peter said unto them, Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost.
Acts 3:19 Repent ye therefore, and be converted, that your sins may be blotted out, when the times of refreshing shall come from the presence of the Lord
Acts 17:30-31 And the times of this ignorance God winked at; but now
commands all men every where to repent: Because he has appointed a day, in which he will judge the world in righteousness

Why do we seldom here this anymore? Has it really been rejected?
One excuse we hear, is that it sounds too much like something we need to do, and isn't salvation all done for us?

What does it mean to repent? Is it really something we need to "do"?

Yet repentance is "big" in the Bible. It's an important ingredient in the battle against sin.

Then again we hear, "oh but it's a gift from God, it's not something we "do".
Yes, it is a gift
and scripture says in Romans 2:4 Do you despise the riches of his goodness and forbearance and longsuffering; not knowing that the goodness of God leads you to repentance?

So we do need to respond to His goodness and forbearance and not turn away from repentance. To turn away is actually "hardening our hearts" against Him! It's not that repentance is somehow secondary to the gospel or an addition to the gospel, it's at the very heart of the gospel. We can't even begin to understand the gospel if we don't understand our need for God's grace and our need to repent.

It sounds like a command: "repent ye", "men should repent", "now commands all men to repent"...

So what exactly is Repentance?

The first step we take in the journey of salvation provided by our Savior, is realizing we need to be saved.
This is the work of the Holy Spirit in our hearts and minds.
John 16:8 And when he (the comforter, the Holy Spirit) comes, he will reprove the world of sin, and of righteousness, and of judgment

On the day of Pentecost we read of Peter preaching a powerful sermon in Acts 3.
The Holy Spirit is present reproving the listeners of sin and of righteousness and of judgement, and the people are "pricked in their hearts" and cry out, "what are we to do?". (Acts 2:37)

Peter answers: Acts 3:19 Repent ye therefore, and be converted, that your sins may be blotted out, when the times of refreshing shall come from the presence of the Lord".
The Holy Spirit again and again leads people to the door of repentance. Alerting us that we have a great need. But though He leads people toward the door of repentance He does not force them to enter.

Everyone has the option to either "harden their hearts" against the call, turn aside and continue in their sinful was, or to repent.
Heb. 3:8, 15 Harden not your hearts, as in the provocation, in the day of temptation in the wilderness...To day if ye will hear his voice, harden not your hearts, as in the provocation.

In the day or time of temptation do we respond to God's call or engage in provocations by which we "try" the patience of God. The verse refers to Israel which rebelled against God; they chose a course that put the divine patience and forbearance to a trial.

To harden our hearts against the call of the Holy Spirit to repentance, leads to eventually rejecting the Holy Spirit and severing His influence over us, and loss of all hope for salvation. (Matt 12:32, Eph. 4:30, 1 Tim 4:2)

So back to the question, what is repentance?

1. Sorrow for sin
But now the question is what does this "sorrow" look like? There are many who are sorry for their wrong actions because the consequences were not pleasant. This is sorrow because things didn't work out, it's not repentance. There is no abhorrence to the sin itself, they would gladly do the sin again if the consequences were removed.

True sorrow comes from a sense of realizing the path we are on is wrong and we want to get off that path. Again the Holy Spirit is absolutely necessary to take us on this next step. But we must let Him lead us. He leads us to Christ. Jesus, Who left the glorious comforts of heaven to come to this world and take the full consequences of sin upon Himself in our behalf that we may be delivered from sin and its consequences! As we yield to the influence of the Holy Spirit of God, the conscience will begin to align to God's ways and the sinner begins to realize something of the importance and beauty of God's law and holiness.
Conviction takes hold that his own ways are rather rotten and a desire to rise to a higher level with God takes hold. The love of God and the beauty of holiness draw the person; a longing for cleansing and being in communion with God takes hold.

2. Turning from sin
Repentance is an about turn, a U-turn. From pursuing selfish pleasure and selfish gains, to living for and with Christ. It's a complete turn in our ultimate goal and purpose for our lives.
Again a repentance such as this is beyond what we can do ourselves. Like David, it means spending time on our knees pleading, "Have mercy upon me, O Lord, create in me a clean heart O God and place a new and right spirit within me. Do not cast me away, take not the Holy Spirit away from me. Restore to me, the joy of your presence and salvation. Hold me up by your Spirit, and deliver me from my sin. (See Psalms 51)

Essential aspect of Repentance

Do not procrastinate. Do not put off the work of repentance and seeking that cleansing of heart and mind promised to those who follow Christ.

Every time we give in to sin, every time we neglect to "do the right thing", there is a reaction within we may not even realize.
It is a hardening of the heart, a weakening of the will, a benumbing of the conscience, making it easier to do and think the wrong thing next time. Strengthening the pathways of sin in our minds.

It is true, the Holy Spirit can, and does, at times break through the barricades that we have built against His voice and wake us up to follow Christ. God does not give up easily but keeps on calling, keeps trying to get through.

But it is dangerous to our eternal salvation, to trifle with the invitations of mercy.
It is unreasonable to think that we can ignore the Spirit of grace, and follow satan's lures (which may not seem that terribly evil to us) day after day, then think in a moment of terrible crises we will change and stand up for what is right.

Just one sinful habit or desire persistently cherished can build a barricade against the power of the gospel. The writer of Proverbs puts it like this:
Proverbs 5:22 "His own iniquities shall take the wicked himself, and he shall be holden (chained, shackled) with the cords of his sins.

To find Repentance --
Think of Jesus love. Think of what He has done -- while we were yet sinners, He died for us, so He can rescue us. He wants to save. But He won't force the will. He pleads, He draws us to Himself, yearning for us to turn from our sins and place ourselves under His love and care. If we are willing He will free us from those cords of sin that bind us in the pits of sin, and He will empower us to walk in the paths of righteousness and light WITH Him.
Repentance is realizing we are sinners, but more it's realizing that sin is evil, sin is abhorrent, we don't want sin anymore, we need help, we want help. We can do nothing for ourselves. We must come to Christ just as we are. Turning from sin is not yet the victory, but it is the necessary beginning step to being freed from sin as we turn to Him our Redeemer and strength!

Repentance vs Penance

Penance is a self punishing activity in an effort to free oneself of sin.

Repentance is acknowledging our sinfulness, turning to a sin pardoning Savior for forgiveness and turning from self to Christ; receiving Christ into our lives through faith allowing Him to live His life in us, thus good works will be manifest.

Martin Luther acknowledged his sinfulness but in his early years he turned to "penance" for a solution. Whipping himself, denying himself of food and comfort, ascending steps on his knees, etc., but penance has no power at all to forgive and cleanse from sin, or relief from guilt.

After he found the gospel in the Bible, he still preached about the offensive character of sin, but now he also found the Savior. Now he taught his students that it is impossible for man, by his own works, to lessen its guilt or evade its punishment. Nothing but repentance toward God and faith in Christ can save the sinner. The grace of Christ cannot be purchased; it is a free gift. Luther counseled the people not to buy indulgences, but to look in faith to a crucified Redeemer. He related his own painful experience on vainly seeking by humiliation and penance to secure salvation, and assured his hearers that it was by looking away from himself and believing in Christ that he found peace and joy. {see GC 129}