In the body of his flesh through death, to present you holy and unblameable and unreproveable in his sight:
In the body of his flesh - the element in which His reconciling sufferings had place. Compare Colossians 1:24, "afflictions of Christ in my flesh" (1 Peter 2:24). Angels, who have not a 'body of flesh,' are not in any way our reconciling mediators, as your false teachers assert, but He, the Lord of angels, who has taken our flesh, that in it He might atone for our fallen manhood. False spiritualism and ascetic contempt of the body led some to doubt as to even Christ's "flesh" (Colossians 2:23) being the sphere of His atoning work.
Through death - `through His х tou (G3588)] death' (which could only take place in a body of flesh like ours, Hebrews 2:14). Flesh is the sphere in which His human sufferings could have place (cf. Ephesians 2:15).
To present you (Ephesians 5:27) - the end of His reconciling atonement by death; not that you might present yourselves. The regenerate derive all their sanctity-imputed, inherent, and actual-from Christ. When we have one of these, we have all.
Holy - positively: in relation to God.
Unblameable and unreproveable - negatively: 'without blemish [as amomous is translated as to Jesus our Head, 1 Peter 1:19] in one's self.' Irreproachable х anengkleetous (G410): one who gives no ground for prosecution] in relation to the world without. Sanctification, the fruit, is here treated of; justification by Christ's reconciliation, the tree, having preceded (Ephesians 1:4; Titus 2:14). Our 'sanctification' is regarded here as perfect in Christ, into whom we are grafted at regeneration (1 Peter 1:2; Jude 1:1): not merely progressive, which is the gradual development of the sanctification which Christ is made to the believer from the first (1 Corinthians 1:30).
In his sight - in God's sight, at Christ's appearing.