St. Nikodemos the Hagiorite. "Exomologetarion: A Manual of Confession".
What is repentance?
My brother sinner, this is the preparation you must undergo before you repent and go to confession. Know firstly that repentance, according to St. John of Damaskos, is a returning from the devil to God, which comes about through pain and ascesis. So you also, my beloved, if you wish to repent properly, must depart from the devil and from diabolical works and return to God and to the life proper to God. You must forsake sin, which is against nature, and return to virtue, which is according to nature. You must hate wickedness so much, that you say along with David: “Unrighteousness have I hated and abhorred” (Ps. 118:163), and instead, you must love the good and the commandments of the Lord so much, that you also say along with David: “But Thy law have I loved” (ibid.), and again: “Therefore have I loved Thy commandments more than gold and topaz” (Ps. 118:127). In brief, the Holy Spirit informs you through the wise Sirach what in fact true repentance is, saying: “Turn to the Lord and forsake your sins... Return to the Most High, and turn away from iniquity, and hate abominations intensely” (Sir. 17:25-26).
The aspects of repentance
Know secondly that the aspects of repentance are three: contrition, confession, and satisfaction.
Contrition is sorrow and perfect grief of the heart, which comes about in a person who, on account of the sins committed, disappointed God and transgressed His divine Law. This contrition comes only to the perfect and those who are sons of God, because it only proceeds from the love for God, just as a son repents simply because he disappointed his father, and not because he was deprived of his inheritance or because he will be ousted from his father’s house. Concerning this the divine Chrysostom says: “Groan after you have sinned, not because you are to be punished (for this is nothing), but because you have offended your Master, one so gentle, one so kind, one Who loves you so much and longs for your salvation as to have given even His Son for you. On account of this, groan.”
Related to contrition is affliction, which is also a sorrow and imperfect grief of the heart, which comes about, not because a person disappointed God by his sins, but because that person was deprived of divine grace, lost Paradise, and gained hell. This affliction belongs to the imperfect, that is, to the hired hands and slaves, because it proceeds not out of love for God, but out of fear and out of love for themselves, just as a hired hand repents on account of losing his wage and a slave repents because he fears the disciplines of his master.
So you also, my brother sinner, if you wish to acquire this contrition and affliction in your heart, and through these for your repentance to be pleasing to God, you must do the following.
Confess to an experienced Spiritual Father
First, search around and learn who is the most experienced Spiritual Father, because Basil the Great says, just as people do not show their maladies and bodily wounds to just any physician, but to experienced physicians who know how to treat them, so also sins must be revealed, not to just anyone, but to those who are able to heal them: “The same fashion should be observed in the confession of sins as in the showing of bodily diseases. As then men reveal the diseases of the body not to all or to chance comers but to those who are experienced in their treatment; so also the confession of sins ought to take place in the presence of those who are able to treat them, as it is written: ‘Ye that are strong bear the infirmities of the weak’ (Rom. 15:1)—that is, take them away by your care.”
How one is to examine his conscience
Second, just as you would sit down and count your money after a certain business transaction, in like manner go to a particular place, my brother, and two or three weeks before going to the Spiritual Father you found, especially at the beginning of the four fast periods of the year, sit down in that place of quietude, and bowing your head, examine your conscience, which Philo the Jew calls: “The testing of the conscience,” and become: “Not a defender, but a judge of your sins,” according to the divine Augustine. Consider, like Hezekiah, the whole span of your life in sorrow and bitterness of soul: “I will ponder all my years in the bitterness of my soul” (Is. 38:15). Consider also how many sins you committed in deed, word, and by coupling with thoughts, after you last confessed, counting the months, weeks, and days. Remember the people with whom you sinned and the places where you sinned, and diligently reflect upon these things in order to find every one of your sins. This is how the wise Sirach counsels you from one side saying: “Before judgment, examine yourself” (Sir. 18:20), and from the other, Gregory the Theologian says: “Examine yourself more than your neighbor. Account of actions is superior to an account of money. For money is subject to corruption, but actions remain.”
And just as hunters are not satisfied with merely finding a beast in the forest, but attempt through every means to also kill it, likewise, my brother sinner, you should also not be satisfied with merely examining your conscience and with finding your sins, for this profits you little, but struggle by every means to kill your sins through the grief in your heart, namely, through contrition and affliction. And in order to acquire contrition, consider how much you have wronged God through your sins. In order to also acquire affliction, consider how much you have wronged yourself through your sins.
Note: Numbering does not match the book.
 “Repentance is the returning from that which is against nature to that which is according to nature, from the devil to God, through ascesis and agony” (De Fide Orthodoxa 2, 30, PG 94, 976A).
 Concerning true repentance, see the Homily on Repentance at the end of this book.
 George Koressios, writing about the Mysteries, adds a fourth aspect of repentance, the loosing of sin (also called “keys”), which happens by the grace of the Holy Spirit through the mediation of the Spiritual Father, and which, he says, especially defines the Mystery of Repentance (from his Theology).
 This grief does not only consist of its sensible manifestations, like groans and tears, but it mainly consists of the interior will of man hating sin and in wishing that sin never occurred, and the resolve to never commit sin again. And note this also, that this grief and contrition of the heart, according to Koressios, is an element of repentance and, as long as it is found in the heart, a person is in the state of repentance. But as soon as grief leaves the heart, so also does a person leave from the state of repentance, which means that grief and contrition must be present in the heart of the penitent perpetually, for in this way is his repentance true. Concerning this grief, see more on it in the Homily on Repentance at the end of this book.
 On II Corinthians, Homily 4, 6, PG 61, 426.
 Some teachers divide the sorrow and the grief which a sinner has on account of his sins into three parts: the grief he has before confession, which they call infliction, or reproach (pros-tribe); the grief he has during confession, which they call contrition (syn-tribe); and the grief which he has after confession, which they call affliction (epi-tribe). [Greek words transliterated for the Web—OCIC Ed.]
 Regulæ Brevius 229, PG 31, 1236A; tr. Ascetic Works of Saint Basil, pp. 313-314.
 My Christian brethren, do not wait until the last moment to confess and go to your Spiritual Father when the days you wish to commune are very near, but go many days in advance. And certainly during the four fast periods of the year, as soon as they begin, go to confession with leisure and when you have time, so you may be properly corrected. One or two days before you are to commune, go to your Spiritual Father so that he may read a prayer of forgiveness over you on account of the pardonable sins which you committed between the time of your confession and your reception of Communion, and so receive in this manner, according to this good custom which is followed by the monks of the Holy Mountain.
 Because the people of today either find it burdensome to carry out this light examination of their conscience, or on account of forgetfulness they are unable to remember their sins, see the pertinent areas of Part 1 of this book, Instruction to the Spiritual Father, which we have prepared for you, brother, in particular, Chapter 3, Concerning Mortal Sins, Pardonable Sins, and Sins of Omission, and Chapter 4, Concerning the Ten Commandments, where we explain who errs in these commandments, in order to lighten your conscience by helping you easily remember your sins. So, look there and examine your conscience and bring to mind the sins you have committed according to what is said there in order to confess them. Read also Chapter 6, Concerning Thoughts, in order to learn from there that you must also confess your bad thoughts, if not all of your thoughts, and certainly those thoughts which disturb you and assault you the most, because just as the eggs of birds, when they are hidden in dung, are enlivened and hatch chicks, so also bad thoughts, when they are not revealed to a Spiritual Father, are vivified and become deeds, according to John of the Ladder: “As hens’ eggs that are warmed in dung hatch out, so thoughts that are not confessed hatch out and proceed to action” (Step 26, PG 88, 1085C; tr. The Ladder, p. 193).
 Carmina Moralia 33, PG 37, 932A.
From Part III, Chapter 1 of Exomologetarion (A Manual of Confession), by St. Nikodemos the Hagiorite (Thessaloniki, Greece: 2006, Uncut Mountain Press). Order today from Uncut Mountain Supply! Posted on 10 March, 2006 (n.s.).