Repentance is real when afterwards you keep trying strenuously to live now as you ought; but without this it is not very effectual, if you repent just to say your sins & to keep on living as before.
It is always possible to make a new start by means of repentance. 'You fell,' it is written, 'now arise'(cf. Prov. 24:16). And if you fall again, then rise again, without despairing at all of your salvation, no matter what happens. So long as you do not surrender yourself willingly to the enemy, your patient endurance, combined with self-reproach, will suffice for your salvation. 'For at one time we ourselves went astray in our folly and disobedience,' says St. Paul. '... Yet He saved us, not because of any good things we had done, but in His mercy' (Tit. 3:3,5).
In words of boastfulness and self-justification there always lie concealed contrariness and pride, from which God turns away. After sinning one ought immediately to 'flee.' But, you will say, where? To the calm haven of heartfelt repentance. Every night before you go to sleep, tell God, the Knower of Hearts, all the sins you have committed in deed, word, and thought, and believe that God receives your heartfelt repentance. At the same time try to render your heart contrite by the memory of sudden death.
According to the degree to which the intellect is stripped of the passions, the Holy Spirit initiates the intellect into the mysteries of the age to be.
The full and complete definition of repentance is that we never again allow in ourselves the sins of which we repent, or whereby our conscience is stung. The mark of satisfaction and forgiveness is when we have driven out from our hearts all desire for them.
Those who have sinned must not despair. Let that never be. For we are condemned not for the multitude of evils, but because we do not want to repent...
By holy baptism original sin is expunged, as also sins committed before baptism. It also eliminates the violent power sin has over us till rebirth; it gives us the grace of the Holy Spirit by which we are united with God in Christ, and we receive power to subdue and conquer sin. For the simple reason that we are not delivered from the struggle with sin, we cannot be entirely free from sin during the whole of our earthly life, and even the righteous man may fall seven times (i.e. often) and rise again by repentance, says Scripture (Prov. 24:16). He falls on account of his weakness and limitations, because he does not always notice sin which subtly and imperceptibly rears its head from his fallen nature, and which is artfully and imperceptibly offered and suggested by fallen spirits. Repentance becomes his secure possession, his constant weapon, his invaluable treasure. By repentance the righteous man maintains his fellowship with Christ. He is healed by repentance from the wounds caused by sin.
He Who before our offence forbids us to sin, after our offence ceases not from waiting for us to repent, He Whom we have rejected calls after us. We have turned away from Him, but He has not turned away from us.
It is more serious to lose hope than to sin. The traitor Judas was a defeatist, inexperienced in spiritual warfare; as a result he was reduced to despair by the enemy's onslaught, and he went and hanged himself. Peter, on the other hand, was a firm rock: although brought down by a terrible fall, yet because of his experience in spiritual warfare he was not broken by despair, but leaping up he shed bitter tears from a contrite and humiliated heart. And as soon as our enemy saw them, he recoiled as if his eyes had been burnt by searing flames, and he took flight...
Painstaking repentance, mourning cleansed of all impurity, and holy humility in beginners, are as different and distinct from each other as yeast and flour from bread. By open repentance the soul is broken and refined; it is brought to a certain unity, I will even say a commingling with God, by means of the water of genuine mourning. Then, kindled by the fire of the Lord, blessed humility becomes bread and is made firm without the leaven of pride. Therefore, when this holy three-fold cord or, rather, heavenly rainbow, unites into one power and activity, it acquires its own effects and properties. And whatever you name as an indication of one of them, is a token also of another. The first and paramount property of this excellent and admirable trinity is the acceptance of indignity with the greatest pleasure, when the soul receives it with outstretched hands and welcomes it as something that relieves and cauterizes diseases of the soul and great sins. The second property is the loss of all bad temper, and humility as its subsiding. The third and highest degree is a true distrust of one’s good qualities and a constant desire to learn.
The grace of repentance, which acts in those who struggle, is a patristic inheritance. It is a divine transaction and exchange in which we give dust and receive heaven. We exchange matter for the Spirit. Every drop of sweat, every pain, every ascesis for God is an exchange.