Tim Keller gave a lecture at Covenant Seminary in 2004 on Preaching to Believers and Unbelievers. He deals with a few very important points. One of them is about the power of the preaching event over the moralistic application of the sermon (evidenced by taking notes). I have quoted Keller on this issue recently. He also deals with Deconstructing Defeater Beliefs in the lecture. Give it a listen.