Romans 8:8

So then they that are in the flesh cannot please God.

Those who are in the flesh — controlled by fallen human nature, the carnal mind, and the natural heart — cannot please God or gain His approval. To be in the flesh is to be governed by a carnal mind that is hostile to God and cannot submit to His law. Opposition to His commandments reveals this condition, and when sin is brought home to the conscience it should lead to humble repentance and confession, not to blame against the law.

To be controlled by the natural heart is to leave the will unsurrendered to God and the heart unshaped by the Holy Spirit, so that enmity toward God is revealed and natural impulses govern. Trying to serve both God and the world leaves worldly aims in control and makes God's Word uncongenial. To be in the flesh is to be willing to gratify the lust of the flesh, including the abomination of self-abuse, and to let bodily desires and evil passions rule. Such rule encourages skepticism about Christian truth and makes doubt appear virtuous.

The fleshly life is shown by worldly customs, selfish ambition, pride, and indifference, revealing a heart yielding to Satan rather than controlled by God's Spirit. It also means not valuing God's high calling, not fulfilling His purpose, failing to meet the conditions plainly marked out in His Word, and professing to be Christian while dishonoring Christ and doing the works of Satan, with defects of character constantly increasing. Those in the flesh cut themselves loose from God so He cannot cooperate with them. They are not sanctified by the truth, do not share in the divine nature, and have not overcome self and the world with its affections and lusts, and they cannot join the holy family of the redeemed.

Those living in the flesh cannot be Christians no matter how high their profession or how devoted they claim to be, and are deceived about themselves if they think otherwise. They prove entirely unfit to serve their Master's interests, cannot be entrusted with God's work and responsibilities, and cannot be safe guides, leaders, and teachers of God's people. The verse draws a divide between being in the flesh and being in the Spirit: those in whom the Spirit of God dwells are no longer in the flesh but belong to Christ and receive life and righteousness through Him. Pleasing God requires seeking His glory in all that is done, being willing to do His will, keeping His commandments with consecrated heart, and being cleansed, renewed, sanctified, and made in character like Christ. It calls for continual watchfulness and prayer to resist carnal influences and for giving work, thoughts, and pleasure to more excellent things.