The Doctrine of Repentance - Thomas Watson - Bog

Repentance is not optional. It is not left to our choice whether or not we will repent, but it is an indispensable command. God has enacted a law in the High Court of heaven that no sinner will be saved except the repenting sinner, and he will not break his own law. No one can willfully continue in sin and expect to be covered by the blood of Christ. Even if all the angels stood before God and begged for the life of an unrepenting person, God would not grant it. The Lord God, compassionate and merciful, . . . who keeps faithfulness for thousands, . . . will by no means leave the guilty unpunished (Exodus 34:6-7). Though God is more full of mercy than the sun is of light, still He will not forgive a sinner who willfully continues to sin.
We have, by sin, wronged God. We have eclipsed his honor. We have infringed upon his law, and we should, reasonably, repent of our old ways. By repentance, we humble and judge ourselves for sin. We agree that God would be righteous if he destroyed us, and so we give glory to God and do what we can to repair his honor.
Dying to sin is the life of repentance. The very day a Christian turns from sin, he must require of himself a perpetual fast. The eye must fast from impure glances. The ear must fast from listening to slander. The tongue must fast from cursing. The hands must fast from bribes. The feet must fast from unclean paths. And the soul must fast from the love of wickedness. This turning away from sin implies a noticeable change in the lives of those who truly follow Christ.
Therefore let us, while we are on this side of the grave, make our peace with God!