Having already established that we were chosen in Christ before the foundation of the world (Eph. 1:4), predestined for adoption, and then shown the grim reality of our former state—dead in sin, enslaved to the flesh, but rescued by the sheer grace of God—Paul opens chapter 3 by unfolding what he calls “the mystery.”
This mystery, long hidden but now revealed, is the astonishing truth that Gentiles are fellow heirs—members of the same body and partakers of the promise in Christ Jesus through the gospel (v. 6). Under the Old Covenant, the promises of God were administered chiefly through Israel. The Gentiles were alienated from the commonwealth and strangers to the covenants of promise (cf. 2:12). But now, through the blood of Christ, the dividing wall has been torn down. The mystery is not that Gentiles could be saved—that was always hinted at in the Old Testament—but that in Christ they are made full co-heirs, entirely equal participants in the blessings of salvation.
This mystery is not a plan B. It is not God improvising after Israel failed. Rather, Paul calls it “the plan of the mystery hidden for ages in God” (v. 9). It was always God’s purpose, now made known through the apostles and prophets by the Spirit. God’s intention is to display His manifold wisdom—not just in human redemption, but through the church, to the heavenly realms (v. 10). That is a staggering thought: the church is not only the means by which the gospel is proclaimed on earth, but also the stage upon which God displays His glory to the unseen powers.
Paul then humbles himself, calling his role in all this “a stewardship of God’s grace” (v. 2) and referring to himself as “the very least of all the saints” (v. 8). Though formerly a persecutor of the church, God entrusted him with the noble task of preaching “the unsearchable riches of Christ” to the Gentiles. He makes clear that this message did not originate with him—it is not man-made, nor the product of reason or philosophy—but comes by revelation, and its content is the boundless grace and glory of Jesus.
Paul ends the chapter with one of the most beautiful doxologies in Scripture:
“Now to him who is able to do far more abundantly than all that we ask or think, according to the power at work within us, to him be glory in the church and in Christ Jesus throughout all generations, forever and ever. Amen.”
— Ephesians 3:20–21 (ESV)
God is not limited by our imagination or expectations. His purposes are deeper, His grace richer, and His power more vast than we can comprehend. And all of this—from predestination, to regeneration, to inclusion in the people of God—serves one ultimate aim: His glory in the church and in Christ Jesus forever.