From Eric Costa at Reformation Theology - here they are, all in one post…
Preach to Glorify God
The ultimate goal of Christian preaching—as with all other things—is the glory of the Triune God. When the minister proclaims God’s true and beautiful Word, he honors the Persons, attributes, and works of God. But the glory really radiates when the Spirit uses his Word to change lives. If someone is convicted, saved, comforted, inspired, redeemed by the preached Word, God was at work, showing himself to be good, sovereign, gracious, and altogether glorious.
Preach to Transform
In order to glorify God, preaching aims at complete redemption and renewal. The goal is to make the hearer better able to engage reality (God, self, others, world, culture, etc.) from a Biblical perspective. Every facet of every life is fair game—if a person thinks, feels, speaks or acts at all, then those ways of participating in God’s world ought to be made to serve God’s glory. Sometimes the transformation is dramatic, as when a person is convicted and converted. Sometimes the change is externally imperceptible, as when a person is reassured once again of God’s love. Always it should be so that the person loves God with his whole heart, soul, mind and strength better than he did when he first sat in the pew.
Preach against Unbelief
In order to transform people, preaching aims to increase their faith. The desired progression is from sin to holiness (sanctification), which requires faith. A person will only be changed through truly believing the Word of God. Whether Christian or not, all of us have the same problem: we do not believe the Word of God enough to let it shape our lives in every way. Therefore the preacher must target the unbelief in the hearer, and proclaim the Word as beacon that draws forth true faith from those in whom the Spirit works.
Preach the Gospel
In order to inspire faith, preaching must convey the Gospel. The Good News is that God is for us in Jesus Christ. Helping the hearer understand this goes well beyond a “simple” evangelistic message. The grace of God addresses us at every point in our lives: it establishes and strengthens our faith (and, therefore, obedience). Certainly, preach the Law as well—bad news often precedes the Good News. But the majestic goodness of God, displayed in the Gospel, must characterize our preaching week in and week out. This wins our faith.
Preach Christ from All the Scriptures
The person and work of Jesus Christ is the substance of the Gospel. The beginning, middle, and end of the Christian life must be informed by the redemption that is in Christ Jesus—all the Scriptures are helpful for this. Jesus himself made it very clear that he is the main subject of all the Scriptures. Paul set the tone for our preaching by saying, “I decided to know nothing among you except Jesus Christ and him crucified.” Friends, a sermon is not Christian unless it is Christocentric.
Preach with Unction
“And when they had prayed, the place in which they were gathered together was shaken, and they were all filled with the Holy Spirit and continued to speak the word of God with boldness.” The anointing of the Spirit is necessary for true boldness in preaching. Apart from the Spirit’s empowerment, a preacher might muster some fervor, but he will lack authority, and might not even possess the courage to maintain God’s truth before sinners. The right proclamation of the Word requires holy unction, which comes by the grace of God through prayer.
Preach with Clarity
God himself has condescended tremendously to help us understand his will. Therefore, preachers have no right to dwell in theological obscurity in their pulpits, but are called to preach with clarity. If it is important that the Gospel be understood by all who hear, then preaching should be not only in the common language, but also concise, uncluttered, logical, and memorable. Preachers do well to improve upon these basics of clear communication as they seek to imitate the Fountainhead of all communication, the Word of God incarnate.