Near the end of his life, Andrew Fuller (1754–1815) ruminated on spiritual preaching in a letter dated February 21, 1813, to his Scottish friend Christopher Anderson.
I have been thinking of late  of the force of the petition, “Take not thy Holy Spirit from me.” As spiritual things are spiritually discerned, if the Lord leave us to ourselves, we shall lose sight of the gospel, and somehow get beside it. I have heard many ingenious sermons, and perhaps preached some, in which the gospel was overlooked; and if a sinner heard it, and never heard the way of salvation before, he might have died, and gone to the bar of God, for any thing he could have heard then, without having been told his danger, or the way of salvation. Take not thy Holy Spirit from us! It is for want of spirituality of mind, surely, that there is so much orthodox, and at the same so little evangelical preaching.
Joseph Belcher, ed., The Last Remains of the Rev. Andrew Fuller (Philadelphia: American Baptist Publication Society, ), 361. For the full text of the letter, see Hugh Anderson, The Life and Letters of Christopher Anderson (Edinburgh: William P. Kennedy, 1854), 214-215.