Addressing the common allegations of a flesh and Spirit opposition as a hermeneutic key to understanding the Fourth Gospel (e.g., Bultmann’s gnostic interpretation), Ridderbos offers a different take. First, reveiwing briefly Bultmaann’s position, according to his view “flesh” and “spirit” denote “the radical opposition between two mutually exclusive metaphysical principles, which he then “demythologizes” and interprets utilizing terms and concepts taken from existentialist philosophy (Ridderbos, The Gospel of John, p. 130). “Flesh,” e.g., speaks of the “nothingness” and “inauthenticity” of human existence, whereas “spirit” refers to “authentic” existence in which “nothingness” ceases to have dominion. Ridderbos, in contrast, rejects an original dualism, pointing out that from the very beginning of the Fourth Gospel, we encounter the notion that the Word is the creation of all things–παντα δι αυτου εγενετο, και χωρις αυτου εγενετο ουδε εν (John 3:3). Commenting further, Ridderbos states,
“The opposition between flesh and Spirit primarily relates therefore to the creatureliness and dependence of humanity in relation to God as Spirit, Source, and Ruler of all life. In that connection, ‘flesh’ does not denote what is ‘lower’ in humankind but the whole human person, physical as well as spiritual. Accordingly, what is opposed to humankind in its ‘authentic existence’ adn threatens us as our ‘fate’ is not our existence as flesh but the radical disturbance that has arisen in that existence as the result of the self-direction that has brought us into a position of estrangement from God, of guilt and powerlessness, of transience, uncertainty, and meaninglessness. Hence, when, as here, the ‘Spirit’ is contrasted with this powerlessness of the flesh to enter the kingdom of God and to inherit the true life, ‘Spirit’ does not denote the great ontological anti-flesh principle, but God himself as the source of life (cf. 1:13) and above all in his restorative and life-renewing power as the only possibility left to humans to save them from lostness and alienation from God and to give them eternal life. [...] The alternatives ‘flesh’ and ‘Spirit’ are not ‘anthropological’ in the sense of humankind as it is and as it should become in order to rise from the inferiority or nothingness of one existence (flesh) to a higher or ‘authentic’ existence (Spirit). The alternatives rather concern humankind in its (fleshly) powerlessness over against the sovereignty of and omnipotence of God (the Spirit), who alone can transform humankind, that is, grant us the needed rebirth from above” (Ibid., p. 131).