Definition
Flesh (Greek: σάρξ sarx) carries a hamartological-soteriological loading in the corpus: it denotes the fallen human nature, the Adamic inheritance that resists God’s Spirit. It is not identical to the body (as a physical organ), but to the human nature as corrupted by sin, incapable from within itself of pleasing God. The flesh is the terrain that Christ crucified on the cross; sanctification is in part the processual working of that crucifixion.
Usage in the Corpus
E.W. Bullinger
Bullinger emphasizes the absolute unrecoverability of the flesh: the old nature is not capable of improvement or religious discipline. Only radical death (dying with Christ) and rebirth can change what the flesh cannot. This is the hamartological foundation of his monergism: if the flesh can contribute nothing, salvation can only come from God.
Cees Noordzij
Noordzij connects flesh to crucifixion: “the crucifixion of the flesh with its passions and desires” (Gal. 5:24) is the way of sanctification. The flesh is the counter-force that must be overcome through self-emptying and surrender to the cross. [Noordzij, Moses and the Way to Sonship]
Watchman Nee & Witness Lee
Nee/Lee distinguish the flesh (the old man, the Adamic soul-force) from the human spirit (which is renewed by the Spirit). The flesh is equated with the undirected soul; sanctification is learning to discern spirit from soul, and crucifying the soul-forces that express themselves apart from God. [Nee/Lee, The Economy of God]