Is Sin Explicable?

I have this thing, where when I get mad, I demand an explanation. Sometimes, this is more important than an apology, though it probably shouldn't be. So for example, if someone calls me, with malicious intent, "Fatty", and once they have expressed sorrow, regret, and everything else, I usually ask, "Okay, but why'd you do it?" I now see that asking such a question may be futile.

God is rational, God is truth, God is beauty, and all that good stuff. God also knows what is truth, but does not know what is false, for it is impossible to know what is false (nor can He be ugly or irrational). God cannot know or do what is not logically possible. Lies, like "Adrian did not type this" cannot possibly be known. So even God cannot know it.

In the same way, I propose that even God cannot know sin. He knows sin exists, but he knows that proposition, not the act. I may know of Obama, but I do not know Obama. Since it is contrary to His nature, can God know the grounding of sin? We look for causes to sin, and we peel back the layers, and we sometimes wonder if there is an infinite regress. Why did you steal my money? Because I wanted it. Clearly, but why didn't you ask to borrow it? Because I didn't want to give it back. Why not? Because I'm greedy. Why did you give in to greed? And then we pause. We want to keep going, but can we?

If to sin is to go contrary to the nature of God, and truth and goodness are essentially the same thing, then we conclude that the cause of sin is not, in principle, explicable. It is not rational. If it is not rational, why ask for causes, as if it were a thing capable of being understood? In a way, it's incoherent, yet we choose to act this way. It is as if to sin is to choose to be insane. Thus, asking for someone for their "reasons" for their sinful actions is like asking the madman why he believes he is a rabbit.