1 Corinthians 3:3

Whereas there is among you envying and strife... are ye not carnal? (1.) The word carnal is here applied to one who not only has his natural use of sense and reason, but also to one who follows the motions and dictates of the flesh, that is, of his animal nature. And, therefore, as S. Thomas rightly remarks, he who follows the motions of lust, or of his fallen nature, is carnal, natural, walking according to man, and destitute of the Spirit of God. (2.) Both here and in Gal. v. 19., the works of the flesh, i.e., of our corrupt nature, include envying, jealousy, strife, which are spiritual sins, as well as gluttony and lust, which are, strictly speaking, fleshly. Cf. notes to Romans 7:22, and Galatians 5:17. The meaning is: You, O Corinthians, are carnal, i.e., contentious, because you fight like boys foolishly about the dignity of your teachers, and extol and put up for sale, one Paul, another Apollos.