When Jesus said “repent and believe” it was not merely a call to stop running away from God and to run to him, but that repentance is as much the mark of the ongoing Christian life as faith. Repentance is not just something the unbeliever does when he turns from sin, but an ongoing self-humbling and self-searching of every true believer. This extract from C.H. Spurgeon’s sermon on Song of Solomon 1:6 makes the point crystal clear.
A man who fears not God, will break all his laws with an easy conscience, but one who is the favourite of heaven, who has been indulged to sit at royal banquets, who knows the eternal love of God to him, cannot bear that there should be any evil way in him that might grieve the Spirit and bring dishonour to the name of Christ. A very little sin, as the world calls it, is a very great sin to a truly awakened Christian.
I will ask you now, dear hearers (most of whom are members of this or of other churches), do you know what it is to fret because you have spoken an unadvised word? Do you know what it is to smite upon your breast, because you were angry?—justly provoked, perhaps, but still, being angry, you spoke unadvisedly. Have you ever gone to a sleepless couch, because in business you have let fall a word, or have done an action which, upon mature deliberation, you could not justify? Does the tear never come from your eye because you are not like your Lord, and have failed where you hoped to succeed? I would give little for your godliness, if you know nothing of this. Repentance is as much a mark of a Christian as faith itself. Do not think we have done with repenting when we come to Christ and receive the remission of our sins by the blood that did once atone. No; we shall repent as long as we sin, and as long as we need the precious blood for cleansing. While there is sin, or a proneness to any kind of sin, lurking in us, the grace of God will make us loathe the sin and humble ourselves before the Most High on account of it.