In one of his Sermones Catholicae, Aelfric of Eynsham (10th c. AD) writes, “The apostle Paul says, that we should arise from the dead in the [same] age which Christ was when he suffered (Se apostol Paulus cwaeð, þaet we sceolon arisan of deaðe on ðaere ylde þe Crist waes þaða he ðrowade, þaet is embe þreo and ðritig geara)” (p. 237). Where, I found myself wondering, does Paul comment on so obscure a question? Aelfric doesn’t quote from Paul directly, but a quick consultation of Augustine’s discussion of the resurrection in De civ. Dei cleared things up:
All shall rise neither beyond nor under youth, but in that vigor and age to which we know that Christ had arrived. For even the world’s wisest men have fixed the bloom of youth at about the age of thirty; and when this period has been passed, the man begins to decline towards the defective and duller period of old age. And therefore the apostle did not speak of the measure of the body, nor of the measure of the stature, but ofthe measure of the age of the fullness of Christ (CD 22.15).
What he’s quoting there is Eph 4:13, which the KJV renders, “Till we all come in the unity of the faith, and of the knowledge of the Son of God, unto a perfect man, unto the measure of the stature (ἡλικίας, maturity or age) of the fulness of Christ.” “ἡλικία,” which admittedly in the Greek probably ought to be glossed as “maturity” in a developmental sense, sometimes also has a more chronological sense (e.g., Matt 6:27), which is how both Augustine’s Old Latin version and Jerome also seem to have taken it: “in virum perfectum in mensuram aetatis plenitudinis Christi.” Read that way, Paul can be read as making a point, not merely about the growth of the church into conformity with Christ, but specifically about the character of that growth, as involving a resurrection to the very age Christ was when he died, in the full flower of adult vigor.