This does not mean that the unsaved person never does anything good, or that the believer never does anything bad. It means that the bent of their lives is different. One lives for the flesh, the other lives for the Spirit. (Wiersbe, W. W. (1996, c1989). The Bible exposition commentary. "An exposition of the New Testament")
However, you are not in the flesh but in the Spirit, if indeed the Spirit of God dwells in you. But if anyone does not have the Spirit of Christ, he does not belong to Him. (NASB)
But ye are not in the flesh, but in the Spirit, if so be that the Spirit of God dwell in you. Now if any man have not the Spirit of Christ, he is none of his. (KJV)
But you are not controlled by your sinful nature. You are controlled by the Spirit if you have the Spirit of God living in you. (And remember that those who do not have the Spirit of Christ living in them do not belong to Him at all.) (NLT)
You, however, are not in the flesh but in the Spirit, if indeed the Spirit of God lives in you. Now if anyone does not have the Spirit of Christ, this person does not belong to him. (NET)
Translation. But as for you, you are not in the sphere of the flesh but in the sphere of the Spirit, provided that the Spirit of God is in residence in you. But, assuming that a person does not have the Spirit of Christ, this one does not belong to Him. Wuest, K. S. (1997, c1984). Wuest's word studies from the Greek New Testament : For the English reader (Ro 8:9).
Here again we have the contrasts presented between life in the flesh (en sarki) and life in the Spirit (en pneumati) with the added dimension of "provided that" (eiper) the Spirit of God dwells (oikeo from oikos - home, therefore to dwell as your home) in you. The indwelling Holy Spirit becomes our seal of the faith and our comforter. The other contrast is the unbeliever versus the believer. Those who do not have Christ's Spirit are not believers at all and do not belong to Christ. The "motions" of our life are the testimony. If our lives reflect the vulgarities of sin then we belong to the ruler of this world and our testimony is of death. If, however, the heart has been made clean and the restoration of the temple has begun then the fruit of the Spirit will be seen as a testimony of life.
The truth is brought out here that the Holy Spirit is given the believing sinner the moment he puts his faith in the Lord Jesus, and not some time afterwards, as is erroneously taught in some quarters, since that believing sinner becomes the possession of the Lord Jesus the moment he believes and thus must possess the Holy Spirit as an indweller. (Wuest, K. S. (1997, c1984). Wuest's word studies from the Greek New Testament : For the English reader (Ro 8:9))
The flesh, the sinful principle, dwelt in them before; and its motions were the proofs of its indwelling; but now the Spirit dwells in them; and its testimony in their conscience, and its powerful operations in their hearts, are the proofs of its indwelling. God made man in union with himself, and his heart was his temple. Sin being committed, the temple was defiled, and God abandoned it. Jesus Christ is come by his sacrifice and Spirit to cleanse the temple, and make man again a habitation of God through the Spirit. And when this almighty Spirit again makes the heart his residence, then the soul is delivered from the moral effects of the fall. And that this is absolutely necessary to our present peace and final salvation is proved from this: that if any man have not the Spirit of Christ - the mind that was in him, produced there by the power of the Holy Ghost - he is none of his; he does not belong to the kingdom, flock, or family of God. This is an awful conclusion! Reader, lay it to heart. (Dr. Adam Clarke)