But it is apparent from our Lord’s description of the subject-matter of the Spirit’s witness that here He has especially in view the function of the Spirit as an inward teacher and strengthener of the moral powers. He is the fellow-witness of the Apostles, mainly and permanently, by enlightening men in the significance of the facts reported by them, and by opening the heart and conscience to their influence. The subject-matter of the Spirit’s testimony is threefold: “He will convict the world in respect of sin, and of righteousness, and of judgment.” I. He should convict the world of sin. No conviction cuts so deeply and produces results of such magnitude as the conviction of sin. It is like subsoil ploughing: it turns up soil that nothing else has got down to. It alters entirely a man’s attitude towards life. He cannot know himself a sinner and be satisfied with that condition. This awakening is like the waking of one who has been buried in a trance, who wakes to find himself bound round with grave-clothes, hemmed in with all the insignia of corruption, terror and revulsion distracting and overwhelming his soul. In spirit he has been far away, weaving perhaps a paradise out of his fancies, peopling it with choice and happy society, and living through scenes of gorgeous beauty and comfort in fulness of interest and life and felicity; but suddenly comes the waking, a few brief moments of painful struggle and the dream gives place to the reality, and then comes the certain accumulation of misery till the spirit breaks beneath its fear. So does the strongest heart groan and break when it wakes to the full reality of sin, when the Spirit of Christ takes the veil from a man’s eyes and gives him to see what this world is and what he has been in it, when the shadows that have occupied him flee away and the naked inevitable reality confronts him.