The Witness of the Spirit.

Romans 8:16
 
“The Spirit itself beareth witness with our Spirit, that we are the children of God.” — Rom. 8:1616The Spirit itself beareth witness with our spirit, that we are the children of God: (Romans 8:16).
It is worthy of note that it is after the apostle has dwelt fully upon the doctrines of justification by faith, and of our place in Christ, that he speaks of this witness of the Spirit of God with ours. He first establishes the soul in Christ Himself. He leads it away from dependence upon the feelings, workings and experiences upon which we are so prone to build, or seek to build, for peace. And he shows us that for fruit also, no less than peace, we must be occupied with Him, who is the only object for faith from first to last. And after having thus enabled us “to give an answer to every man that asketh a reason of the hope that is in us” according to Scripture itself the only sure and infallible authority, he speaks of the Spirit itself bearing witness with our spirit to this blessed fact, that we are children of God, and if children heirs, &c.
Now, first of all, what is the witness of our Spirit with which the Spirit of God bears (as the word means) joint witness? Many have taken it to be the evidence of our lives, the fruits of the Spirit in us I but this is completely opposed to the whole line of the apostle’s argument up to this. Christ, not our fruits or evidences, is our peace; nor do we trust in Him for salvation as saints, but as sinners, (see chapters 5:5-10). The Spirit of God does not occupy us with our own virtues or graces, but with Christ, and that equally for salvation, peace and holiness.
If we turn to 1 Corinthians 2:11,11For what man knoweth the things of a man, save the spirit of man which is in him? even so the things of God knoweth no man, but the Spirit of God. (1 Corinthians 2:11) we find however the “spirit of man” as that part of man to which all human understanding is, ascribed. In Matt. 13:2323But he that received seed into the good ground is he that heareth the word, and understandeth it; which also beareth fruit, and bringeth forth, some an hundredfold, some sixty, some thirty. (Matthew 13:23) moreover the “understanding” of the word of the Gospel is marked as the distinctive feature of the who received the seed into good ground. Now no man has this understanding naturally; the Spirit of God must work in him to produce it (1 Cor. 2:1414But the natural man receiveth not the things of the Spirit of God: for they are foolishness unto him: neither can he know them, because they are spiritually discerned. (1 Corinthians 2:14)). But where this Divine understanding of the Gospel exists, the sinner learns what Christ has wrought for sinners, learns what has made peace for him with God, and rests in Him to whom he is assured of welcome.
He has thus the evidence of his own spirit, that he is a child of God. The word of God has given him a sure ground of confidence; and believing God’s record about His Son, he sets to his seal that God is true.
Upon this faith in Christ the Spirit of God now puts His seal: “in whom after that ye had believed ye were sealed with that Holy Spirit of promise, which is the earnest of our inheritance” (Eph. 1:1313In whom ye also trusted, after that ye heard the word of truth, the gospel of your salvation: in whom also after that ye believed, ye were sealed with that holy Spirit of promise, (Ephesians 1:13)). It is then not merely that I have Scriptural reason for my hope. I have the Spirit of God Himself, possessing me with the consciousness of my blessed portion. Scripture still abides as my justification of the hope I have, — justification, whether to myself or others. And thus I am clear from fanaticism, and from self-deception. The “joint” witness of the Spirit with my spirit, is practically the witness of the Spirit and the Word.
And this is in perfect harmony with the general tenor of Scripture. Everywhere you find in it how the Word and the Spirit go together, where there is true work in the soul. The “water” and the “Spirit” of the 3rd of John (explained by Ephesians 5:26,26That he might sanctify and cleanse it with the washing of water by the word, (Ephesians 5:26) and 1 Peter 1:23, 2523Being born again, not of corruptible seed, but of incorruptible, by the word of God, which liveth and abideth for ever. (1 Peter 1:23)
25But the word of the Lord endureth for ever. And this is the word which by the gospel is preached unto you. (1 Peter 1:25)
), link these together in the work of our new birth. Elsewhere; because so acting by the Word, the Spirit of God is Himself called “living water” (John 7:38, 3938He that believeth on me, as the scripture hath said, out of his belly shall flow rivers of living water. 39(But this spake he of the Spirit, which they that believe on him should receive: for the Holy Ghost was not yet given; because that Jesus was not yet glorified.) (John 7:38‑39)). Again, if sanctification is by the Spirit, it is also by the “truth.” (John 17:1717Sanctify them through thy truth: thy word is truth. (John 17:17)). Nor are we to believe every Spirit, but to “try the spirits whether they are of God” (1 John 4:11Beloved, believe not every spirit, but try the spirits whether they are of God: because many false prophets are gone out into the world. (1 John 4:1)), assured that the true Spirit of God will not fear the test of His own Word.
The witness of the Spirit is not then a mere feeling or emotion of which I can give no account. This is most earnestly to be insisted on. Once separate it from the witness of the Word and you are open to the grossest possible self-deception; you supersede that which is the light unto the feet and lamp unto the path; you land in a world of, it may be, fatal illusion.
On the other hand, the witness of the Word itself is feeble and inefficacious, even in the heart of one truly born of God, except there be along with it the joint witness of the Spirit. It is this that makes evident how by grieving the Holy Spirit of God, whereby we are sealed to the day of redemption (Eph. 4:3030And grieve not the holy Spirit of God, whereby ye are sealed unto the day of redemption. (Ephesians 4:30)), we may fail to make sure (to our own souls) our calling and election; and become such as are blind and cannot see afar off, and forget that We were purged from opt old sins (2 Peter 1:9, 199But he that lacketh these things is blind, and cannot see afar off, and hath forgotten that he was purged from his old sins. (2 Peter 1:9)
19We have also a more sure word of prophecy; whereunto ye do well that ye take heed, as unto a light that shineth in a dark place, until the day dawn, and the day star arise in your hearts: (2 Peter 1:19)
).
In a word, — Christ witnessed to by the Word it the alone object of faith, and just as much for peace as for salvation itself. We trust Him, and as sinners: not our evidences, fruits, or faith itself. And it is while resting in Him and occupied with Him, the Spirit gives its witness with our spirit that we are His, — children of God and heirs, joint heirs with Christ Himself.