St. John of Kronstadt:

Firmly purpose in your soul to hate every sin of thought, word, and deed, and when you are tempted to sin . . .

Icon of St. John of Kronstadt“Firmly purpose in your soul to hate every sin of thought, word, and deed, and when you are tempted to sin resist it valiantly and with a feeling of hatred for it; only beware lest your hatred should turn against the person of your brother who gave occasion for the sin.  Hate the sin with all your heart, but pity your brother; instruct him, and pray for him to the Almighty, Who sees all of us and tries our hearts and innermost parts. ‘Ye have not yet resisted unto blood, striving against sin.’ (Hebrews 12:4)  It is impossible not to often fall into sin unless you have a hatred of it implanted in your heart.  Self-love must be eradicated.  Every sin comes from the love of self.  Sin always appears, or feigns to be, to wish us well, promising us plenteousness and ease.  ‘The tree was good for food, and it was pleasant to the eyes, and a tree to be desired to make one wise.’ (Genesis 3:6)  This is how sin always appears to us.”

+ St. John of Kronstadt, My Life in Christ

St. Theophan the Recluse:

. . . if we undertake to cure ourselves, then we will be able to do something about it.

“If [the disease of sin] is natural, then it cannot be cured. Thus it would remain always, no matter how hard you worked to rid yourself of it. If you accept this thought, you will lose heart, and say to yourself: this is how it is. For this is that woeful despair, which, once it has been introduced into people, they have given themselves over to lasciviousness, to work all uncleanness (Ephesians 4: 19). “I shall repeat again: Maintain the conviction that our disorderliness is not natural to us, and do not listen to those who say, ‘It is no use talking about it, because that is just how we are made, and you cannot do anything about it.’ That is not how we are made, and if we undertake to cure ourselves, then we will be able to do something about it.”

St. Barsanuphius of Optina:

Prayer in church is important. The best thoughts and feelings come in church, yes, and the enemy attacks more violently . . .

St. Barsanuphius of Optina“Prayer in church is important. The best thoughts and feelings come in church, yes, and the enemy attacks more violently in church, but with the sign of the Cross and the Jesus Prayer, you drive him away. It is good to stand in some dark corner in church and to pray to God. “Let us lift up our hearts!” the priest exclaims, but our mind often creeps along the ground, thinking about indecent things. Fight against this.”

+ St. Barsanuphius of Optina,