In nearly every text of Scripture a moral principle can be found, shown through the character of God or Christ, displayed in the good or bad examples of characters in the text, or provided as explicit commands, promises, and warnings. This moral principle is important and must be distilled clearly. But then a crisis is created in the hearers as they understand that this moral principle creates insurmountable problems. I describe in my sermons how this practical and moral obligation is impossible to meet. The hearers are led to a seemingly dead end, but then a hidden door opens and light comes in. Our sermons must show how the person and work of Jesus Christ bears on the subject. First we show how our inability to live as we ought stems from our forgetting or rejecting the work of Christ. Then we show that only by repenting and rejoicing in Christ can we then live, as we know we ought.
– Tim Keller