How understanding of what, exactly? I suppose you mean sin, right?
God knows everything we have done, and already knows everything we will do. He knows what caused us to do these things, if we enjoyed doing them, and if we regret doing them. He also considers if we consented to these things willingly, or if our consent was forced from us. I suppose that God’s judgement of a particular sin takes these things into account, in addition to to the severity of the sin.
So, I would say that He is the most understanding being.