Repentance is the renewal of baptism. Repentance is a contract with God for a second life. A penitent is a buyer of humility. Repentance is constant distrust of bodily comfort. Repentance is self-condemning reflection, and carefree self-care. Repentance is the daughter of hope and the renunciation of despair.
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.'
They (namely the Apostles) have not handed down everything in writing, but have also delivered many things in unwritten form. The former and the latter are equally trustworthy, and so we also consider the [unwritten] Tradition of the Church to be trustworthy. Is it Tradition? Seek no further.
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.
Remember, O my soul, the terrible and frightful wonder: that your Creator for your sake became Man, and deigned to suffer for the sake of your salvation. His angels tremble, the Cherubim are terrified, the Seraphim are in fear, and all the heavenly powers ceaselessly give praise; and you, unfortunate soul, remain in laziness. At least from this time forth arise and do not put off, my beloved soul, holy repentence, contrition of heart and penance for your sins.
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.
Whoever repents sincerely is prepared to withstand any sorrow: hunger and homelessness, cold and heat, illness and poverty, humiliation and banishment, lies and slander, for the soul seeks God and does not concern itself with anything worldly, but instead prays with a clear mind.
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.
True repentance consists of withdrawing from sin and nurturing hatred for it. For, lo, when someone says from his heart: I have hated deceit and been repelled by it - then God accepts him with joy.
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.'
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.
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.
You will not perish on account of thoughts with which you do not sympathize and from which you at least try to be freed. Only repent, & humble yourself. And God will forgive you.