The saint of God[, St. Agathon,] constantly and strictly attended to himself and said that without intense self-examination, no person can achieve success. This is the path to salvation. The saints of God, who constantly examined themselves, constantly found within themselves new failing, and once they found them, they plunged ever deeper into repentance that purified them and prepared them for heaven. On the contrary, evil inattentiveness and busyness are always connected with a profound ignorance concerning oneself; not surprisingly, such self-ignorance is always very self-satisfied and proud of itself. "Many delude themselves," said Blessed Theophylact, "with vain hope, thinking that they will receive the kingdom of heaven, and they in advance add themselves to the ranks of those who rose up because of their virtue, imagining great things about themselves.... Many are called, because God calls many, even all, but there are few chosen, few who are saved, few who are worthy of being chosen by God. To call is God's work, but to be chosen is ours: the Jews were called, but were not chosen, for they were not obedient to the One Who called.
St. Arsenius, who was great among monks, during the entire course of his life, whenever he did manual labor, put a kerchief on his knees because of the amount of tears that fell from his eyes. He died. Abba Pœmen, a father who was gifted with unusually profound spiritual discernment, said upon hearing of this man's death, "You are blessed, Arsenius, for you wept for yourself during this life. Whoever does not weep for himself here will weep eternally. It is impossible to run away from weeping. Either you weep here willingly, or you will weep there unwillingly, in tortures." Hearing of this death, Patriarch Theophilus of Alexandria said, "Blessed are you, Abba Arsenius! You constantly remembered the hour of your own death."
St. Ignatius Brianchaninov, "A Homily on Death" in The Threshold: Trials at the Crossroads of Eternity, trans. Nicholas Kotar, The Collected Works of St Ignatius (Brianchaninov), vol. 3 (Jordanville: Holy Trinity Publications, 2023), 88.