The motto of all true servants of God must be, ‘We preach Christ; and him crucified.’ A sermon without Christ in it is like a loaf of bread without any flour in it. No Christ in your sermon, sir? Then go home, and never preach again until you have something worth preaching.
Leave Christ out? O my brethren, better leave the pulpit out altogether. If a man can preach one sermon without mentioning Christ’s name in it, it ought to be his last, certainly the last that any Christian ought to go to hear him preach.
Leave Christ out of the preaching and you shall do nothing. Only advertise it all over London, Mr. Baker, that you are making bread without flour; put it in every paper, ‘Bread without flour’ and you may soon shut up your shop, for your customers will hurry off to other tradesmen. … A sermon without Christ as its beginning, middle, and end is a mistake in conception and a crime in execution. However grand the language it will be merely much-ado-about-nothing if Christ be not there. And I mean by Christ not merely his example and the ethical precepts of his teaching, but his atoning blood, his wondrous satisfaction made for human sin, and the grand doctrine of ‘believe and live.’
– this excerpt compiled from 3 of Spurgeon's sermons