The preacher’s task is to leave that stone in their path. Never mind if they pick it up, look at it, and throw it away: they cannot keep on throwing it away forever. It is the cornerstone of their lives and finally they must reckon with it. The only obedience that God asks of the preacher is that he does not attempt to change the shape of that stone in order to make it fit more easily into some other place in the building. That stone is meant for judgment as well as for fulfillment. It is uncut by human hand. The preacher is as bound by its nature and its function as are those to whom he preaches. Jesus Christ is both the preacher’s message and his limitation.

D. T. Niles, The Preachers’ Task and the Stone of Stumbling, p. 15