Of all I would wish to say this is the sum; my brethren, PREACH CHRIST, always and evermore. He is the whole gospel. His person, offices, and work must be our great, all-comprehending theme. The world needs to be told of its Savior, and of the way to reach him . . . Blessed is the ministry of which CHRIST IS ALL . . . No Christ in your sermon, sir? Then go home, and never preach again until you have something worth preaching.
(HT: Darryl Dash)
A bit of advice for preachers, just my 2 cents, take it or leave it:
If you preach the gospel consistently and "thickly" for any sustained period of time, at some point someone will get tired "hearing the same old thing" and ask you to preach something else for a change: steps to this, tips for that, lessons on tithing or honoring our parents or what-have-you.
Your response to this objector should be to preach the gospel to them.