The woman caught in adultery, like the ending of Mark, is not original. It shows Jesus vividly expressing wisdom and grace. I think that's why it is such a memorable story and is used so often to describe Jesus. I am sensitive about how portions of the Bible, especially ones like this, can be taken to construct an inadequate view of Jesus. This is done from this passage frequently.
Jesus summons God, who he says they do not know, as his witness. They think he is suicidal. This discussion is even less clear to me than chapter six. Some left him, and others believed. I don't think they get, "the one who sent me" talk.