For those who live according to the flesh set their minds on the things of the flesh, but those who live according to the Spirit, the things of the Spirit. Romans 8:5 NKJV
No person ever becomes better or worse. A person’s state may become better or worse, but his nature remains precisely what it is. When one is saved, that nature does not become better; his sinful nature received from Adam remains as sinful as ever. But he receives from God a new nature that is itself absolute perfection. It is the nature seen in the Person of the Lord Jesus—a nature characterized by the living power of the Spirit of God, and therefore called “the Spirit,” in contrast to “the flesh.”
An unbeliever has only his fleshly nature, and therefore his mind is set on fleshly things—things of which he himself is the center. The believer, having the two natures, may give in to that which is fleshly and be unhappy, but his true character is to set his mind on things of the Spirit, of which Christ is the center. He is “in the Spirit,” not “in the flesh,” as we find in Romans 8:9: “But you are not in the flesh but in the Spirit, if indeed the Spirit of God dwells in you. Now if anyone does not have the Spirit of Christ, he is not His.” The Christian may have a struggle in choosing purposefully to judge and turn from the temptations of the flesh, but the power for overcoming is not in himself. It is in the Spirit of God, who dwells within him.
More than this, the Spirit of God does not draw attention to His own work in the heart of the believer, making him look inward at his own condition. In fact, the Spirit’s power at work in the soul will turn our eyes away from ourselves to the blessed Person of the Lord Jesus Christ at the Father’s right hand, to see in Him every perfection, every godly virtue, and every excellence that delights the Father’s heart. What power there is in being focused on this wonderful Savior!