And so the _substance_ of the Spirit's evidence is the direct conviction based on the revelation of God's infinite love and fatherhood in Christ the Son, that God is my Father; from which direct conviction I come to the conclusion, the inference, the second thought, Then I may trust that I am His son. But why? Because of anything in me? No: because of Him. The very emblem of fatherhood and sonship might teach us that _that_ depends upon the Father's will and the Father's heart. The Spirit's testimony has for form my own conviction: and for substance my humble cry, 'Oh Thou, my Father in heaven!' Brethren, is not that a far truer and nobler kind of thing to preach than saying, Look into your own heart for strange, extraordinary, distinguishable signs which shall mark you out as God's child--and which are proved to be His Spirit's, because they are separated from the ordinary human consciousness? Is it not far more blessed for us, and more honouring to Him who works the sign, when we say, that it is to be found in no out-of-rule, miraculous evidence, but in the natural (which is in reality supernatural) working of His Spirit in the heart which is its recipient, breeding there the conviction that God is my Father? And oh, if I am speaking to any to whom that text, with all its light and glory, has seemed to lift them up into an atmosphere too rare and a height too lofty for their heavy wings and unused feet, if I am speaking to any Christian man to whom this word has been like the cherubim and flaming sword, bright and beautiful, but threatening and repellent when it speaks of a Spirit that bears witness with our spirit--I ask you simply to take the passage for yourself, and carefully and patiently to examine it, and see if it be not true what I have been saying, that your trembling conviction--sister and akin as it is to your deepest distrust and sharpest sense of sin and unworthiness--that your trembling conviction of a love mightier than your own, everlasting and all-faithful, is indeed the selectest sign that God can give you that you _are_ His child. Oh, brethren and sisters! be confident; for it is not false confidence: be confident if up from the depths of that dark well of your own sinful heart there rises sometimes, through all the bitter waters, unpolluted and separate, a sweet conviction, forcing itself upward, that God hath love in His heart, and that God is _my_ Father. Be confident; 'the Spirit itself beareth witness with your spirit.'
II. And now, secondly, That cry is not simply ours, but it is the voice of God's Spirit.
Our own convictions are ours because they are God's. Our own souls possess these emotions of love and tender desire going out to God--our own spirits possess them; but our own spirits did not originate them. They are ours by property; they are His by source. The spirit of a Christian man has no good thought in it, no true thought, no perception of the grace of God's Gospel, no holy desire, no pure resolution, which is not stamped with the sign of a higher origin, and is not the witness of God's Spirit in his spirit. The passage before us tells us that the sense of Fatherhood which is in the Christian's heart, and becomes his cry, comes from God's Spirit. This passage, and that in the Epistle to the Galatians which is almost parallel, put this truth very forcibly, when taken in connection. 'Ye have received,' says the text before us, 'the Spirit of adoption, whereby _we_ cry, Abba, Father.' The variation in the Epistle to the Galatians is this: 'Because ye are sons, God hath sent forth the Spirit of His Son into your hearts, _crying_ (the Spirit crying), Abba, Father.' So in the one text, the cry is regarded as the voice of the believing heart; and in the other the same cry is regarded as the voice of God's Spirit. And these two things are both true; the one would want its foundation if it were not for the other; the cry of the Spirit is nothing for me unless it be appropriated by me. I do not need to plunge here into metaphysical speculation of any sort, but simply to dwell upon the plain practical teaching of the Bible--a teaching verified, I believe, by every Christian's experience, if he will search into it--that everything in him which makes the Christian life, is not his, but is God's by origin, and his only by gift and inspiration. And the whole doctrine of my text is built on this one thought--without the Spirit of God in your heart, you never can recognise God as your Father. That in us which runs, with love, and childlike faith, and reverence, to the place 'where His honour dwelleth,' that in us which says 'Father,' is kindred with God, and is not the simple, unhelped, unsanctified human nature. There is no ascent of human desires above their source. And wherever in a heart there springs up heavenward a thought, a wish, a prayer, a trembling confidence, it is because that came down first from heaven, and rises to seek its level again. All that is divine in man comes from God. All that tends towards God in man is God's voice in the human heart; and were it not for the possession and operation, the sanctifying and quickening, of a living divine Spirit granted to us, our souls would for ever cleave to the dust and dwell upon earth, nor ever rise to God and live in the light of His presence. Every Christian, then, may be sure of this, that howsoever feeble may be the thought and conviction in his heart of God's Fatherhood, _he_ did not work it, he received it only, cherished it, thought of it, watched over it, was careful not to quench it; but in origin it was God's, and it is now and ever the voice of the Divine Spirit in the child's heart.