Someone asked Abba Isaiah, ‘What is repentance and what does “to flee from sin” mean?’

He replied, ‘There are two ways: one of life and one of death (cf. Jr 21:8 and the Didache). The person who walks along one does not progress along the other. The person who walks along both is not yet reckoned for the kingdom, or for punishment. When such a person is dead, his judgement is in the hands of God, who also has mercy. Whoever wishes to enter the kingdom keeps watch over his actions because the kingdom puts an end to every sin. The enemies sow (cf. Mt 13:39) but their thoughts do not grow. If, through the Spirit, a person contemplates the loving kindness of the Godhead (cf. 1 P 2:3) the arrows of the enemy do not penetrate him (cf. Ep 6:16). He is, in effect, putting on the armour of virtues (cf. Ep 6:11), which guards against the enemy, taking care not to allow him to be troubled. If frees him in order that, in his contemplation, he may see, know and distinguish between the two ways, fleeing from one and embracing the other.”

[Abba Isaiah of Scetis, Ascetic Discourses, Discourse 21]