That this paradox is so, i.e. that the appropriation of humanity by the divine Logos at his incarnation is tantamount to the formation of the Church as his body, in an objective sense, even before any human persons joined it as members, is evident in Eph. 5,22-30, where the unity between man and woman in the Sacrament of Marriage is placed parallel to the unity between Christ and the Church after the incarnation. The expressions: “as Christ loved the Church and gave himself up for her” (Eph. 5,25. Cf., Acts 20,28), and “that he might sanctify her, having cleansed her by the washing of water with the word” (v.26), suggest the objective existence of an entity before the incarnation proper living in sin, which the Son took to himself by becoming human and cleansed it. Christ’s body here is the entire human nature “per se”, not the body’s human members who are added to it by appropriating to themselves the human nature of the Son. Human nature cleansed from sin comprises the Church as Christ’s and so human persons are added to it as its members afterwards, so that we can say that as Christ’s body the Church exists as an objective reality even before or regardless of its members. The Church exists objectively at the incarnation and because of it, even without members. Christ’s human nature, being his human body, is the place within which he works out eternally the redemption and salvation of each particular human person and through them the salvation of the entire created order, to which humanity belongs (Cf.Rom. 8,14ff).
Now we can understand better Christ’s expression “in me” (εν εμοί) in John 6,56 and 15,1-10, as well as Paul’s frequent expression “in Christ” (εν Χριστώ) denoting not man’s identification with or absorption by Christ, but his unity with and in Christ’s humanity. Man’s unity with Christ does not deform him, but conforms him “to the image” of the incarnate Son (Rom. 8,29. 2Cor. 3,18. Gal.2,20.), which has nothing to do again with the idea of “corporate personality”. In the Church, the relationship is a member relationship to the head and the body, the whole Christ. In the same sense is also understood Paul’s formula “in Christ” with reference to Christ’s correspondence with Adam which defines the relationship between the “one” and the “many”. On account of the unity or the oneness of human nature, Adam’s fall extends to all of his descendants, while their individuality is preserved by their active participation in Adam’s sin when each human person does exactly what Adam did in the past, being thus for it personally responsible: “εφ’ ω πάντες ήμαρτον» (“because all men sinned on account of it”, Rom. 5,12). Influenced by satan fallen human persons inherit Adam’s sin which is “Like the transgression of Adam” («επί τω ομοιώματι της παραβάσεως Αδάμ»,Rom. 5,14). This fact rules out the rabbinic idea, according to which Adam constitutes the coherence of mankind in the sense that all men were created “in him”. Restricting the hereditary transmission of the original sin and ignoring Satan’s role in it, we are forced to deny the existence of righteous men in the Old Testament, on the one hand, and accept the universal salvation of all men by Christ without their active appropriation of his saving work to themselves, on the other. In this case, personal freedom and responsibility are done away with, and together with them active membership in the Church as well. In Paul’s expression “for as in Adam all die, so also in Christ shall all be made alive” (1Cor. 15,22), we must understand the fall and restoration of human nature as objective conditions to which men participate personally by their own free will. Being unable to achieve salvation because of his fallen nature, man in Christ obtains it by actively sharing in Christ’s human nature cleansed from sin. This is why the Old Testament law could not save man (Heb. 7,19), even though, as God’s work, the law was “holy” and “good” and “spiritual” (Rom. 7,12-16), being thus restricted to the role of “our custodian until Christ came” (Gal. 3,23). Conditions changed however, when "God has done what the law, weakened by the flesh, could not do: sending his own Son in the likeness of sinful flesh and for sin he condemned sin in the flesh, in order that the just requirement of the law might be fulfilled in us, who walk not according to the flesh but according to the Spirit” (Rom. 8,3-4). Thus, “in Adam” and “in Christ’ we understand human nature in its two conditions: of sinfulness and sinlessness, i.e. the body of Adam, human nature, and “the body of Christ which is the Church” (Col. 1,24).