Toward the end of his Lectures on Eloquence, John Witherspoon warns against young persons, and young preachers in particular, exaggerating their exhortations to others.
He warns that we should not make virtue so high that no one can attain it and vice so dastardly that no one feels in danger of it.
But I have often observed with most regret upon this subject is young persons carrying the things that are really true and excellent to a certain excess or high pitch that is beyond nature, and does not tend in the least to promote conviction, but rather hinders it. When men speak of virtue or true goodness, they are apt to raise the description beyond the life in any real instance, and when they speak of vice and its consequences they are apt to draw the character so as it would apply only to a few of the most desperate profligates, and the miserable state to which they reduce themselves. This rather seems to fortify the generality of persons to whom these descriptions do not apply, in their careless and secure state.
Similarly, Witherspoon warns against being too slow to sympathize with sufferers and too quick to point them to heroic fortitude:
Once more I have often observed young persons frequently choose as their subject afflictions, of which probably they have had very little experience, and speak in such a high style as if every good man were, as the heroes of old, above the reach of every accident. And it is true that an eminent saint is sometimes made superior to all his sufferings; but generally speaking, we ought to be very tender of sufferers, till we ourselves have been in the furnace of affliction; and after that we shall not need be told so.
Read through these two paragraphs again, especially if you are a young minister. They will save you and your people a lot of unnecessary pain.