This reminds me of a friend of mine.
This friend firmly believes that there can be no regret if you make a choice in life "that was the best choice at the time, given the knowledge available."
I get that perspective, I really do.
But what it's really saying is:
"I don't want to be blamed for a choice that was the best choice at the time, given what I knew then."
Here's the thing, though. It's not about blame in a moral sense. I don't think God is saying to us, "I labeled this action bad for an arbitrary reason. You did it. Therefore I label you with a guilty label." That's a childish approach to God and a childish approach to life.
Rather, if we, for whatever reason, even unwillingly, are wrapped up in a destructive act, we need to turn from that act. If I kill someone by accident, I'm not guilty in a moral/external sense. Nobody is going to blame me. But I was *coupled* with that event, an event that is part of the larger suffering of humanity. And while we are not "legally" responsible for the individual sins of mankind, we certainly are responsible as members of one another and as high priests of creation.
And so I need to come to terms with such an event as best I can, by exercising my function as a royal priest of God (and we believe that we are all royal priests) and name that event for what it is. Name that event as something that was providentially God's will, yes, but, if it is destructive and evil, something that he does not want as part of the Reign of Heaven. God told us to "name the beasts" and I believe that means to call out the reality of something, the truth in something. Even tragedies we were only indirectly a part of. Even honest mistakes.
So let's say you had pre-marital sex with someone. Someone you didn't have any intention of being with for very long, if at all. You can say, "You know what? That act was not devoid of any attempt at beauty or love or truth; there really is something struggling to be good, and even something struggling to become like God there. But it was wrapped up in destruction and tragedy, and I was part of it, and so I turn from it."