Spurgeon preaching on John 14:16-17,
We are told in the text, that Jesus would send the Comforter, who would abide in the saints for ever; who would dwell with them and be in them… Know ye not that ye are temples of the Holy Ghost? for he dwelleth in you. That man is no Christian who is not the subject of the indwelling of the Holy Spirit: he may talk well, he may understand theology and be a sound Calvinist; he will be the child of nature finely dressed, but not the living child. He may be a man of so profound an intellect, so gigantic a soul, so comprehensive a mind, and so lofty an imagination, that he may dive into all the secrets of nature; may know the path which the eagle’s eye hath not seen, and go into depths where the ken of mortals reacheth not; but he shall not be a Christian with all his knowledge; he shall not be a son of God with all his researches; unless he understands what it is to have the Holy Ghost dwelling in him, and abiding in him, yea, and that for ever.
Charles Spurgeon, The New Park Street Pulpit, vol. 1, p. 30