The success of a man lies when his flesh has no say in his decision making. Walk in the Spirit, and you shall not fulfill the lust of the flesh” (Gal. 5:16).
The human flesh is always in opposition with the spirit, the flesh contradicts what the spirit wants, permits me to say that they are enemies.
And do not grieve the Holy Spirit of God, by whom you were sealed for the day of redemption” (Eph. 4:30). The flesh graves the Holy Spirit the moment we sin against God.