From: The Way of Life, chapters 6-7, by Charles Hodge:
There is no duty the necessity of which is either more obvious in itself, or more frequently asserted in the word of God, than that of repentance. Nature itself teaches us, that when we have done wrong, we should be sorry for it, and turn away from the evil. Every man feels that this is a reasonable expectation in regard to those who have offended him. Every parent, especially, looks with anxiety for the repentance of a disobedient child; and he considers nothing worthy of the name, but sincere sorrow and a return to affectionate obedience. No man need wonder, therefore, that God, who requires nothing but what is right, and who can require nothing less, commands all men everywhere to repent. The salvation offered in the gospel, though it be a salvation of sinners, is also a salvation from sin. The heaven which it promises is a heaven of holiness. The rivers of pleasure, which flow from the right hand of God, are filled with the pure waters of life. No man, therefore, can be saved who does not, by repentance, forsake his sins. This is itself a great part of salvation. The inward change of heart from the love and service of sin to the love and service of God, is the great end of the death of Christ, who gave himself for his church, "that he might sanctify and cleanse it with the washing of water by the word, that he might present it to himself a glorious church, not having spot, or wrinkle, or any such thing; but that it should be holy and without blemish." A salvation for sinners, therefore, without repentance, is a contradiction.
Hence it is that repentance is the burden of evangelical preaching. Our Saviour himself, when he began to preach, said, "Repent: for the kingdom of heaven is at hand." And when he came into Galilee preaching the gospel, he said, "The time is fulfilled and the kingdom of God is at hand: repent ye, and believe the gospel." The commission which he gave his apostles was, "That repentance and remission of sins should be preached in his name among all nations." In the execution of this commission his disciples went forth and preached, "Repent ye, and be converted, that your sins may be blotted out, when the times of refreshing shall come from the presence of the Lord." Paul, in the account which he gave Agrippa of his preaching, said that he "showed first unto them of Damascus, and at Jerusalem, and throughout all the coasts of Judea, and then to the Gentiles, that they should repent and turn to God, and do works meet for repentance." And he called upon the elders at Ephesus to bear witness that he had taught "publicly, and from house to house, testifying both to the Jews, and also to the Greeks, repentance toward God, and faith toward our Lord Jesus Christ."
Repentance, then, is the great, immediate, and pressing duty of all who hear the gospel. They are called upon to forsake their sins, and to return unto God through Jesus Christ. The neglect of this duty, is the rejection of salvation. For, as we have seen, unless we repent we must perish. It is because repentance is thus indispensably necessary, that God reveals so clearly not only the evil of sin, and the terms of his law, but his infinite compassion and love; that he calls upon us to turn unto him and live, assuring us that he is "The Lord, The Lord God, merciful and gracious, long-suffering, and abundant in goodness and truth," This call to repentance commonly follows men from the cradle to the grave. It is one of the first sounds which wakes the infant's ear; it is one of the last which falls on the failing senses of the dying sinner. Everything in this world is vocal with the voice of mercy. All joy and all sorrow are calls to return unto God with whom are the issues of life. Every opening grave, every church, every page of the Bible, is an admonition or an invitation. Every serious thought or anxious foreboding is the voice of God, saying, "Turn ye; for why will ye die?" It is through all these admonitions that men force their way to death. They perish, because they deliberately reject salvation.
It is one of the mysteries of redemption, that, under the economy of mercy, all duties are graces. Though repentance is our duty, it is not less the gift of God. Those who wrest the Scriptures to their own destruction, gladly seize on such truths either as an excuse for delay, under pretence of waiting God's time, or as a palliation of the guilt of a hard and impenitent heart. But those who feel the greatness of the work required of them rejoice in the truth, and rouse themselves with new energy to their duty, no longer a hopeless task, and with all earnestness work out their own salvation, because it is God that worketh in them to will and to do according to his own pleasure.
I concur with Dr Hodge on this. What think ye?