I think you've all got the wrong idea about metanoia, however:
"As far as the prodigal son, his returning was the fruit of his repentance not repentance itself."
The main point of the parable is not the repetence of the son, but the greeting of the father. It didn't make any difference to the father what his son had done. The son, on the other hand, in order to return to the father, had to lose every "thing" that meant anything to him, every "thing" his father had given him and including his own sense of self importance; in other words, he had to die to himself and in that state realize that his only hope was that his father, whom he realized he loved still loved, him and would take him back, even as a sort of slave. But his father greeted him and treated him as a prince.
One can "end up" in that state of personal nothingness and helplessness, or one can strive through a sort of praxis to arrive at the same end, dying to the self. In the first instance one can end up humble enough to come crawling back and be received like a prince, to speak in temporal terms, or simply dissolve into some sort of depraved end. In the other, one can experience the uncreated light of God, to speak in theological terms. Neither way is even remotely easy.
"The main point of the parable is not the repetence of the son, but the greeting of the father. It didn't make any difference to the father what his son had done"
I think that's what I said way back in reply #10027.
"Notice the Greek conjunction "but" that limits what the son is doing and changes the emphasis of the parable to what the father is doing. He could care less what the son is saying or doing, just that "my son was dead, and is alive again; he was lost, and is found". For that, there is joy in the house."
I agree that repentance is dying to self, for it is a turning away from the direction you are going, here self will, and changing direction.
Kolo, there are a couple of things you say here that I think are eisegetical.
First of hall, the idea that the son 'had to' go through all of these things to come back. I don't believe that is the case. The son, as a son, could have turned around at any point and could have avoided a whole lot of bad effects of the sin in his life. Nothing made him cease being a son. He didn't realize this for he would have disowned himself if the shoe were on the other foot - yet, he was born a son and nothing could make him cease from being a son. Not even 'death'.
Second, I think it is eisegesis that the son realized how much he loved the father. I don't know that we see that here. He realized what he had done wasn't working. He remembered the good old days with the father. But he hoped that he could make a deal with the father to where he could be a servant. He just knew he couldn't be a son any more - after all, that's the way he himself would have treated any son who had done to him what he had done to the father- if even that good. So, devoid of anything he could offer the father but service, he went with his tail between his legs to beg for mercy. I think the love for the Father came after he experienced the Father's mercy (and is something we don't see in the parable)- for only after his restoration could he understand and appreciate how great the Father's love was for him.
It is true, the greeting of the Father is of key importance to the parable. The Father saw the son and went running to him. The son had nothing, could do nothing, came empty handed. The Father, out of pure grace, mercy, and love, restored him to all of his former glory.
But there is another point that all of us have ignorred here. It is in the elder son.
The elder son did all the right things, stayed with the Father, and he never strayed. He was the poster-boy for right living. When the son who had strayed returned, the elder son was indignant. He said "look at me! I stayed with you. I served you faithfully these many years. I never transgressed! Look at how good I was. And this other son, he spent all of your blessings on depravity! And yet, you accept him back and give him your very best! " (definite paraphrase)
At this point, in the parable, Jesus does something interesting. In verse 31, rather than calling him "huios" or "son" (a term used throughout the parable to this point), he says "teknon" or "child".
Since Jesus is speaking to the Pharisees, his overall point seems to be that the faithful children of the Father should rejoice and not act like spoiled children when the one who has strayed returns and love that person as a full brother without undue burden or conditions of acceptance.