This is a great Spurgeon excerpt I found at Phil Johnson's blog Pyromaniac.
"I have heard it said that the way Luther preached would not suit this age. We are too polite! The style of preaching, they say, that did in John Bunyan's day, is not the style now. True, they honor these men; they are like the Pharisees; they build the sepulchers of the prophets that their fathers slew, and so they do confess that they are their father's own sons, and like their parents. And men that stand up to preach as those men did, with honest tongues, and know not how to use polished courtly phrases, are as much condemned now as those men were in their time; because, say they, the world is marching on, and the gospel must march on too.
No, sirs, the old gospel is the same; not one of her stakes must be removed, not one of her cords must be loosened. "Hold fast the form of sound words, which thou hast heard of me, in faith and love which is in Christ Jesus." Theology hath nothing new in it except that which is false. The preaching of Paul must be the preaching of the minister to-day. There is no advancement here. We may advance in our knowledge of it; but it stands the same, for this good reason, that it is perfect, and perfection can not be any better.
The old truth that Calvin preached, that Chrysostom preached, that Paul preached, is the truth that I must preach to-day, or else be a liar to my conscience and my God. I can not shape the truth. I know of no such thing as the paring off the rough edges of a doctrine. John Knox's gospel is my gospel. That which thundered through Scotland must thunder through England again. The great mass of our ministers are sound enough in the faith, but not sound enough in the way they preach it.
Election is not mentioned once in the year in many a pulpit; final perseverance is kept back; the great things of God's law are forgotten, and a kind of mongrel mixture of Arminianism and Calvinism is the delight of the present age. And hence the Lord hath forsaken many of his tabernacles and left the house of his covenant; and he will leave it till again the trumpet gives a certain sound. For wherever there is not the old gospel we shall find "Ichabod" written upon the church walls ere long.
The old truth of the Covenanters, the old truth of the Puritans, the old truth of the Apostles, is the only truth that will stand the test of time, and never need to be altered to suit a wicked and ungodly generation. Christ Jesus preaches to-day the same as when he preached upon the mount; he hath not changed his doctrines; men may ridicule and laugh, but still they stand the same—semper idem written upon every one of them. They shall not be removed or altered."
--Charles Spurgeon, excerpt from his sermon "The Immutability of Christ," Jan. 1858