St. Mark the Ascetic: Enduring Sorrows which are the result of Sins

 If you wish to bring to God a blameless confession, then do not call to mind the images of previous sins, but courageously endure all the sorrows that come upon you as a result of these sins. Sorrows come as retribution for previous sins, the heaviness of each retribution depending on the heaviness of the sin. He who is wise and knows the truth confesses to God not by calling to mind his committed sins, but by enduring the sorrows that come as a result of those sins. If he rejects suffering and dishonor, he will not bring repentance even if he does other good deeds, for vanity and lack of suffering serve sin, even when the ascetic does good deeds.

+St. Mark the Ascetic, from On Those Who Think they are made Righteous by Works, in The Philokalia Volume 1, #193, 197,150-156

Elder Aimilianos of Simonopetra: The role of pain

At the beginning, after the Fall, man himself sensed and realized that what had appeared as a curse - namely, God's decision that he should live by the sweat of his brow, bear children with pain, and rediscover paradise "through many tribulations" (Acts 14:22). hid what was in fact God's love, that it comprised a way and means for man's second creation, for his renewal who had fallen away and was dying. On his maturing, man recognized in his sufferings, in his labor and sweat, and even in his death, that his pain encompassed a means of expression, a living possibility for his presenting and revealing himself to God, of confessing to Him his longing for the deification now lost. This is to say that he, man, found no better way of expressing his yearning for deification that by suffering pain for the sake of God.
+Elder Aimilianos of Simonopetra, from Martyrdom: Foundation of Orthodox Monasticism, in The Living Witness of the Holy Mountain: Contemporary Voices from Mount Athos, translation with introduction and notes by Archbishop Alexander (Golitzin).