This gets to the core of my beliefs. I believe that we are children of God. He is the literal father of our spirits. Our purpose is to become as He is. to grow into the spiritual beings that He is. We come here to decide what we want. We need to choose for ourselves between good and evil. In the course of our learning, we all inevitably choose wrong. Once we have chosen wrong--even just once-- we are not nor can we of ourselves be made perfect. THAT requires the intercession of one without sin. In other words, my finite imperfections must be swallowed up in someone else's infinite perfection if I am to be pronounced clean and rise above the sum of my mistakes and transgressions.