"Together with" is the force of
the Greek used in this passage. It does not say that He bears witness _to_
our spirit but "_together_ with" it. How He does this is explained in Gal
iv. 6, "Because ye are sons, God hath sent forth the Spirit of His Son
into your hearts, crying, Abba, Father." When we have received Jesus
Christ as our Saviour and accepted God's testimony concerning Christ that
through Him we have become sons, the Spirit of His Son comes into our
hearts filling them with an overwhelming sense of sonship, and crying
through our hearts, "Abba, Father." The natural attitude of our hearts
towards God is not that of sons. We may call Him Father with our lips, as
when for example we repeat in a formal way, the prayer that Jesus taught
us, "Our Father, which art in heaven," but there is no real sense that He
is our Father. Our calling Him so is mere words. We do not really trust
Him. We do not love to come into His presence; we do not love to look up
into His face with a sense of wonderful joy and trust because we are
talking to our Father. We dread God. We come to Him in prayer because we
think we ought to and perhaps we are afraid of what might happen if we did
not. But when the Spirit of His Son bears witness together with our spirit
to our sonship, then we are filled and thrilled with the sense that we are
sons. We trust Him as we never even trusted our earthly Father. There is
even less fear of Him than there was of our earthly father. Reverence
there is, awe, but oh! such a sense of wonderful childlike trust.

Notice when it is that the Spirit bears witness with our spirit that we
are the children of God. We have the order of experience in the order of
the verses in Rom. viii. First we see the Holy Spirit setting us free from
the law of sin and death, and consequently, the righteousness of the law
fulfilled in us who walk not after the law but after the Spirit (vs. 2-4);
then we have the believer not minding the things of the flesh but the
things of the Spirit (v. 5); then we have the believer day by day through
the Spirit putting to death the deeds of the body (v. 13); then we have
the believer led by the Spirit of God; then and only then, we have the
Spirit bearing witness to our sonship. There are many seeking the witness
of the Spirit to their sonship in the wrong place. They practically demand
the witness of the Spirit to their sonship before they have even confessed
their acceptance of Christ, and certa