In creating the whole of existence, G‑d made forces that reveal Him and forces that oppose Him—He made light and He made darkness. One who does good brings in more light. One who fails, feeds the darkness.
But the one who fails and then returns transcends that entire scheme. He reaches out directly to the Essential Creator. Beyond darkness and light. And so, his darkness becomes light.
I'm a big a big fan of the Repair Jack series of books by F. Paul Wilson and just reading this today made me believe now more than ever that Wilson must have known of the Rebbe. The whole supernatural series is based on dark (for evil) and light (for non-evil) and what's written above could have been the plot for each novel.
Okay, there was more stuff going on in the sci-fi books, but still, the whole dark and light thing is totally Wilson. Now as always, time to choose sides.