Woe is he who knowingly chooses to sin with the intention to repent when morning comes, for he knows not what the coming day or the night that precedes it will bring.
If the main goal of the repentant sinner should be total, light-bearing and blessed communion with God, then the main hindrance to this is the existence of the passions still active and working in him - the virtues being as yet unsealed in him - and the unrighteousness of his powers. Therefore his main work upon conversion and repentance should be the uprooting of the passions and sealing the virtues - in a word, correcting himself.
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.
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.
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.
A man who falls into sin is different from the way he was created. He is different, because he changes by his own actions the way he was meant to be. Man renounces himself when he becomes a different person through repentance. He leaves a corrupted man, which he had become through sin, and becomes such as he once was created, through mercy.
When it is painful to remember the past, it is better to simply repent of what had been bad, and think no more about it. In order not to despair or be enfeebled by it, 'remember the examples of God's great mercies to great sinners. The main thing: do not condemn, do not envy, know yourself and be with God.'
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.
One day, a young monk came to see an elder and asked him, 'What must I do, Father? I fall continuously in the same sin.' The elder replied, 'If you fall into sin, get up and do penance.' Monk: 'And if I fall again?' Elder: 'Then get up and repent of your sin again.' Monk: 'But until when?' Elder: 'Until your death.'
First, one prays with the simplicity typical of beginners and by shedding copious tears. All this is due to the grace of God which is called purifying grace, which catches us like a fish-hook, and guides us towards repentance. For it is our God, Who is good in all and to all, Who finds us. He sees us. He invites Himself known to us first. Then we get to know Him, after He anoints us with His divine mercy. Hence, repentance, mourning, tears, and everything that happens to someone who repents, is all due to divine grace. This is purifying grace which cleanses man.