c.1400, "physical, human, mortal," from Old French carnal and directly from Medieval Latin carnalis "natural, of the same blood," from Latin carnis "of the flesh," genitive of caro "flesh, meat" (see carnage). Meaning "sensual" is from early 15c.; that of "worldly, sinful" is from mid-15c. Carnal knowledge is attested from early 15c. and was in legal use by 1680s.
Unconverted men are so called (1 Cor. 3:3). They are represented as of a "carnal mind, which is enmity against God" (Rom. 8:6, 7). Enjoyments that minister to the wants and desires of man's animal nature are so called (Rom. 15:27; 1 Cor. 9:11). The ceremonial of the Mosaic law is spoken of as "carnal," because it related to things outward, the bodies of men and of animals, and the purification of the flesh (Heb. 7:16; 9:10). The weapons of Christian warfare are "not carnal", that is, they are not of man's device, nor are wielded by human power (2 Cor. 10:4).