The Mind Set on the Flesh
"The mind that is set on the flesh is hostile to God, for it does not submit to God's law; indeed, it cannot. Those who are in the flesh cannot please God."
Paul's focus in Romans 8 can be summed up as "life in the Spirit," as the chapter continually emphasizes the work of the Holy Spirit in the one who has trusted in Christ alone for salvation. Among the greatest privileges Christians experience is the indwelling of the Holy Spirit, and it is by the Spirit alone that believers grow in the grace and knowledge of Christ.
Because the Holy Spirit dwells within us, we presently enjoy the life of the world to come. We will consider this more in a few days when we study Romans 8:10-11. Today, we are in verses 7-8, which illustrate the reality of life in the Spirit by way of a contrast, explaining to us why those who live in the flesh cannot enjoy true life either now or in the age to come. First, we must note that while there is a sense in which Christians can live in the flesh—according to the remnants of fallen human nature that still plague us—believers do not set their minds on the flesh the way that unregenerate people do. By no means are we downplaying the difficulty of ongoing sin in the believer's life. Christians can even fall into grievous sin, and we must never think that there is any transgression that we are above committing. Scripture shows us that true believers can murder, commit adultery, and even deny Christ (2 Sam. 11-12; Matt. 26:69-75). Nevertheless, there is a change that happens upon conversion that means we are no longer in the flesh. We sin and grieve the Spirit, but the true believer in Jesus never finds lasting satisfaction in doing so. Christians are not controlled by the mindset of the flesh, for if we were, we could not persevere in faith, and perseverance in faith is granted to all who are justified in Christ (Rom. 8:29-30; Phil. 2:12-13).
The unconverted—those who set their minds on the flesh—cannot experience true life either now or in the age to come. Fleshly minds do not submit to the law of God (Rom. 8:7). In fact, they do all they can to suppress it and its conviction (1:18-3:20). Moreover, the mind set on the flesh is hostile to God. It cannot please the Lord in any sense. It wants nothing to do with God and—in the supreme display of irrationality—causes a person to hate God so much that he would rather suffer in hell than please the Lord in heaven. As long as people are in the flesh, they cannot please God in any way (8:8). This means that they cannot even make the choice to trust Christ, a choice that is indeed pleasing to the Lord, for to trust in Jesus alone for salvation is to give up our rejection of God and His standards. Because of our fallenness, God must give us faith in Jesus if we are to believe.
Coram Deo
In his commentary Romans, John Murray says that to be hostile to God "is nothing other than total depravity and 'cannot please God' is nothing less than total inability." On our own, we are so hostile to God that we would have nothing to do with Him. If He were merely to knock at the doors of our hearts, it would not be enough. To save us, He must crash through the door, for we would never invite Him in otherwise.