St. Dorotheos of Gaza: On remembering evil

 There are times when, with apparent sincerity, a man asks forgiveness of his brother after some discord between them or for some quarrel which has arisen, and yet after the reconciliation he still remains troubled and has hard thoughts against his brother. He ought not to dwell on such thoughts but to cut them off immediately, for this is remembering evil. It needs much self control not to prolong such thoughts and fall into danger.

+St. Dorotheos of Gaza, from Dorotheos of Gaza: Discourses and Sayings, chapter 8 On Rancor or Animosity.

St. Ieronymos of Aegina: Let us see to it that we repent.

I pray to God not to take my soul until I have time to repent sincerely. Because God desires sincere repentance, not that which is hypocritical and just humble talk. 

Two elders once quarreled and one went to the other to ask forgiveness. But he was not sincere and humble, and did not ask forgiveness from from his heart. The other was discerning; he perceived it and didn't forgive him. The first went to a spiritual father and said to him, "I quarreled with so-and-so and whereas I asked his forgiveness, he won't forgive me. What should I do?" The father answered him, "You didn't ask from your heart, that's why he didn't forgive you." After a little while he went back with sincere repentance and said to him, "I am the one at fault, forgive me." And then he forgave him. So it is with God. He doesn't listen to the words, He looks at the heart. As long as we have time, therefore, let us see to it that we repent.

+St. Ieronymos of Aegina, from The Elder Ieronymos of Aegina by Peter Botsis, chapter 20, Daily Ministry