The Angelic Doctor Against the Errors of the Greeks - Chapter 16

 How God is to be understood as not dwelling in men before the incarnation of Christ.

Doubt provoking also is a statement of Athanasius to Serapion: “According to the forechoice of the divine counsel it was impossible that the Church of the Lord should directly receive an invisible form, incorporeal and unclothed, but the Lord made himself of one substance with the Church by assuming her form to himself.”  This would seem to imply that before the incarnation of Christ God did not dwell in man by grace. Certain heretics  presumptuously asserted this while commenting on the Gospel of John (7:39): “As yet the Spirit had not been given, because Jesus was not net glorified.”

Both texts are to be interpreted in the same way. For just as it is said that the Holy Spirit was not given previously because he was not yet given with the same fullness as when he was received by the Apostles after the resurrection of Christ, so the Church was not able to receive the gift of grace with the same fullness as, in accord with the divine ordinance, she received it through the incarnation of Christ, since grace and truth as John says (1:17) came through Jesus Christ. Therefore, in his discourse on the Council of Nicaea Athanasius says: “It is indeed impossible that they should be consummated and perfected unless I assume a perfect man.”  This is to be understood in the sense above.

There, however, the qualification “in accord with the divine forechoice” was added, because, although it was possible for God by his absolute power to confer the perfection of grace on the human race in a way other than the incarnation of Christ, it was not possible, given the divine ordinance, for the human race to acquire this fullness of grace in any other way.