Before I begin postings of reflections on repentance, I'd like to offer this definition of repentance from the OrthodoxWiki website:
Repentance is the feeling and act in which one recognizes and tries to right a wrong, or gain forgiveness from someone whom he wronged. In religious contexts it usually refers to repenting for a sin against God. It always includes an admission of guilt, and also includes at least one of the following: a solemn promise or resolve not to repeat the offense; an attempt to make restitution for the wrong, or in some way to reverse the harmful effects of the wrong where possible.
In Biblical Hebrew, the idea of repentance is represented by two verbs: שוב shuv (to return) and נח nicham (to feel sorrow).
In the New Testament, the word translated as 'repentance' is the Greek word μετάνοια (metanoia), "after/behind one's mind," which is a compound word of the preposition 'meta' (after, with), and the verb 'noeo' (to perceive, to think, the result of perceiving or observing). In this compound word the preposition combines the two meanings of time and change, which may be denoted by 'after' and 'different'; so that the whole compound means: 'to think differently after'. Metanoia is therefore primarily an after-thought, different from the former thought; a change of mind accompanied by regret and change of conduct, "change of mind and heart", or, "change of consciousness". One of the key descriptions of repentance in the New Testament is the parable of the prodigal son found in Luke 15:11-32.
Phew...that was so much easier than trying to explain it myself...I especially like that "change of consciousness" explanation. It is kinda like "Wake up! Look around! Think through your life and be honest with yourself and make a change!" Or as the parable linked to above says about the prodigal son "But when he came to himself..."(verse 17). It seems to me that a life lived in repentance is one in which you become more and more awake, a coming to yourself. Unfortunately, this current age in which we live has more and more in which to put us to sleep, more ways in which to distract ourselves from facing reality and to just float along at the surface. To ease our pains, instead of turning to repentance from which we will find healing, we turn to the safety of entertainment in all of its various forms. We have become a generation quite adept at pain avoidance.
In every worship service in Orthodox Christianity we pray "that we may complete the remaining time of our life in peace and in repentance...". Without repentance, salvation as defined by the Orthodox Church is unattainable, plain and simple. You can't go around cheating people or gossiping or casting people into eternal torment and fully expect, because you call yourself a Christian and go to church and read your Bible, that you will find salvation. It is non-sensical to even suggest that this could be possible.
"When Jesus heard it, He said to them, “Those who are well have no need of a physician, but those who are sick. I did not come to call the righteous, but sinners, to repentance." Mark 2:17
And if the Apostle Paul can align himself with sinners, "this is a faithful saying and worthy of all acceptance, that Christ Jesus came into the world to save sinners, of whom I am chief." 1 Tim 1:15, then it goes without saying that I am too.
So I think I've made my case about the importance of repentance. Next up, quotes from those who have lived their lives in repentance and have run the race in such a way that they have received their prize. 1 Cor 9:24.