Using expository preaching would solve another problem. I call it pulling Oreo cookies out of a Vanilla Wafer box. False advertising or packaging, if you please. This happens when a man reads his text or passage and then preaches a message that might be very good in content but is not related to his text. You sit there bewildered trying to figure out why he used the text he did. Since the Biblical definition of preaching is proclaiming or heralding the truth, let us do that and stop trying to be flowery orators with no power.
V. You can preach the WHOLE counsel of God systematically.
Some people will never hear a message out of Obadiah, Habakkuk, Philemon or Hebrews (unless it is Hebrews 13:17) because the Spirit just never seems to lead the preacher to those books. Yet, God took the trouble to lead someone to write those books. I am sure He must want them read and taught.
Systematic preaching, which still needs the Spirit’s leading and anointing to be effective, will give new converts time to grow before you hit some sore spots. It also gives you more opportunity to meet more people’s needs more often. Repetition is good and God does repeat doctrines. However, if you pick a list of four or five dirty subjects and continually hammer those points you will desensitize your people. You will also miss a lot of other sins as well as leave many needs unmet as you try to meet those needs based only upon your feelings or perspective.
Constant repetition of a dirty dozen of do’s (or don’ts) can lead to a false sense of security and self-righteousness while carnality is rampant in the pews. A member may attend faithfully, tithe, not smoke or drink but, what about his pride, peevishness, laziness, etc?
VI. Principles taught now prepare for applications later.
I have found it is best to lay solid bedrock of principles before you make specific applications. Humanism, materialism, New Age philosophy, and many other "isms" have so infiltrated the church that people are usually not able to bear some applications before learning the Biblical principle supporting it. Issues are seen as the preacher’s opinions or convictions and not necessarily relevant to anyone else. If they are accepted, it is often because of the charisma of the preacher. If another man comes along with greater charisma and different convictions, the people will follow him because the man has touched them rather than the issues.
Teaching principles and the Biblical definition of separation will give the Christian something to chew on while the Holy Spirit works on him. By the time, you get to the Scripture that will make a specific application of the principle there may be no controversy. Examples would be music, clothing drinking, hair, etc. The Holy Spirit may have already convicted someone to give up or start something before you ever get to the appropriate Scriptures. Then when you touch on it in your preaching you will get an "AMEN!" instead of a "Stone him!" or an "Oh, me!" rather than an "OUT YE!" You may still get rebellion when you name the sin or make the application of the principle. It is far better that they react to the Word or the Spirit’s conviction than to you as a person. You can rest in the fact that you were faithful and God can handle the arguments that people have with Him.