CARNAL. Fleshly, with reference to the body as the seat of the desires and appetites; usually used in Scripture in the negative sense, as opposed to the spiritual. In 1Cor.2.14-1Cor.3.4, Paul divides mankind into two classes—the natural and the spiritual; this corresponds to the classification of people as once-born and twice-born. Then he classifies Christians as “carnal” and “spiritual” (kjv; niv has “worldly” and “spiritual”) and lists the marks of carnality as “jealousy and quarreling” and undue emphasis on personalities: “I follow Paul—I follow Apollos.” “Carnal” does not necessarily imply active and conscious sin but is opposed to “spiritual” (Rom.7.14; 2Cor.10.4; Heb.7.16; Heb.9.10). It describes the dominance of the lower side of human nature apart from God’s work in one’s life.
The KJV OT uses the expression “lie carnally” to describe adultery (Lev.18.20) and fornication (Lev.19.20), but these words are used far more often figuratively to refer to idolatry. To take the love that belongs to husband or wife and give it to another is adultery, and to take the love that belongs to God and give it to another is idolatry (Hos.1.1-Hos.1.11-Hos.3.1-Hos.3.5; Rev.17.18).——ABF
CARNAL (σαρκικός, G4920; σάρκινος, G4921); fleshly, in the manner of the flesh, belonging to the realm of the flesh, opposite of spiritual.
Connecting carnal with the mind, declares it to be “enmity against God” (Rom 8:7), a disposition so widely diffused in humanity, with such ascendancy over man that it is confirmed dislike to God, opposition to His will, and determination to frustrate the divine will by substituting self-will for His will.
The adverb, carnally, is an OT term describing forbidden sex relations (Lev 18:20; 19:20). The offender is so dominated by fleshly lusts that reason is ignored, God’s will despised and inherent rights of others violated. The term, used once in the NT (Rom 8:6 KJV), is without sexual connotation.
International Standard Bible Encyclopedia (1915)
Is there any difference between sarkinos and sarkikos? The former more definitely denotes the material of which an object is made. It may express with emphasis the idea of sarkikos, the spiritual given up as it were to the flesh.
See MAN (THE NATURAL).