5 which in other ages was not made known to the sons of men, as it has now been revealed by the Spirit to His holy apostles and prophets:
Verse five states the meaning of the “mystery” presented earlier in the chapter. This verse develops further the idea of the New Testament mystery.
“Which” refers to “the mystery of Christ” presented in verses three and four.
in other ages
No one understood the idea of the church in previous “ages”—that is, in “other” ages, meaning in a different kind of age. (A second Greek word exists for “other” that means another of the same kind, but that is not the word used in this verse.) The dispensation of the law is different from the dispensation of grace.
was not made known to the sons of men,
People in Old Testament times did not know that Gentiles would be incorporated into God’s plan by the launching of the church.
as it has now been revealed
There was no revelation of the church previous to Paul (Co 1:26). The word “now” indicates that God revealed the church age to New Testament apostles (2:20; 4:11). “Revealed” means to unveil something that was not seen before. The Greek tense indicates that God revealed it to Paul and the apostles at one point (aorist).
Paul wrote over 30 years after the day of Pentecost, the beginning of the economy of the church. God’s revelation to Paul was not that the church existed; rather, He revealed the development of the doctrine of the church.
by the Spirit
The Holy Spirit is the agent of revelation. He gave apostles and prophets the truth of the doctrine of the church age (2 Pe 1:20-21). The Spirit revealed the doctrine of the church age to Paul.
to His holy apostles and prophets:
The idea of the mystery of the church was revealed to “apostles and prophets” of the New Testament. These leaders were “holy” in the sense that God set them apart for special service. The apostles and prophets were “holy” because God set them aside specifically to launch the church.
Paul was the publisher of the doctrine of the mystery, but all of the apostles and prophets knew about the dispensation of grace. Apostles and prophets were God’s vehicles for communicating the idea of the church to people in the first century.
The church was a new concept revealed in the economy of grace.
The church did not exist in the Old Testament (Co 1:26). The “mystery” was hidden from ages and from generations, but at the time of the New Testament God revealed it to His saints. The theocracy of the nation Israel ended on the day of Pentecost.