Clement of Rome emphasizes the importance of holiness in every aspect of a believer's life, both in body and spirit. He contrasts the characteristics of those who are truly believers, filled with the Spirit of Christ, with those who exhibit the works of the flesh, listing various sins and behaviors that are contrary to God's law. Clement warns against the dangers of allowing the mind of the flesh to dominate, as it leads to enmity towards God and the absence of the Spirit of God within. He references the departure of the Spirit of God from Saul as a cautionary example of the consequences of lacking the Spirit of God.

For, if a man be only in name called holy, he is not holy; but he must be holy in everything: in his body and in his spirit. And those who are virgins rejoice at all times in becoming like God and His Christ, and are imitators of them. For in those that are such there is not the mind of the flesh. In those who are truly believers, and in whom the Spirit of Christ dwells — in them the mind of the fleshcannot be: which is fornication, uncleanness, wantonness; idolatry, sorcery; enmity, jealousy, rivalry, wrath, disputes, dissensions, ill-will;drunkenness, revelry; buffoonery, foolish talking, boisterous laughter; backbiting, insinuations; bitterness, rage; clamour, abuse, insolence of speech; malice, inventing of evil, falsehood; talkativeness, babbling; threatenings, gnashing of teeth, readiness to accuse, jarring,disdainings, blows; perversions of the right, laxness in judgment; haughtiness, arrogance, ostentation, pompousness, boasting of family, of beauty, of position, of wealth, of an arm of flesh; quarrelsomeness, injustice, eagerness for victory; hatred, anger, envy, perfidy, retaliation; debauchery, gluttony, overreaching (which is idolatry), the love of money (which is the root of all evils); love of display, vainglory, love of rule, assumption, pride (which is called death, and which God fights against). Every man with whom are these and such like things— every such man is of the flesh. For, he that is born of the flesh is flesh; and he that is of the earth speaks of the earth, and his thoughts are of the earth. And the mind of the flesh is enmity towards God. For it does not submit itself to the law of God; for it cannot do so, because it is in the flesh, in which dwells no good, because the Spirit of God is not in it. For this cause justly does the Scripture say regarding such a generation as this: My Spirit shall not dwell in men for ever, because they are flesh. Whosoever, therefore, has not the Spirit of God in him, is none of His: as it is written,The Spirit of God departed from Saul, and an evil spirit troubled him, which was sent upon him from God.