The Church of Christ has been in the mind and plan of God before the foundation of the world. Here in Eph. 3:9, Paul calls it a mystery. The word “mystery” does not mean in Scripture what it means in today. Today it means something that we try to figure out what it is or what is happening.
Paul says that it was his privilege to “bring to light” this mystery. In the fullness of time God had sent forth His Son to redeem mankind. He came to this sin cursed word to accomplish that. After He arose from the dead and went back to Heaven in the Ascension, the Church of Christ was established on the first Pentecost after Jesus’ resurrection.
The mystery here is that both Jews and Gentiles alike can and do share in the Church. This verse reminds us of the fact that the Son of God was involved in creation.
In eph. 3:10 we’re told that God has the wisdom to devise the great salvation plan through Christ. God could have chosen any medium to accomplish this but He chose to reveal it through the Church. The Church is God’s instrument to reveal this plan where both Jew and Gentile can obtain salvation.