To them God has chosen to make known among the Gentiles the glorious riches of this mystery, which is Christ in you, the hope of glory. He is the one we proclaim, admonishing and teaching everyone with all wisdom, so that we may present everyone fully mature in Christ.
This passage speaks to the mystery of the gospel, which is that Christ is in us, and through His indwelling presence, we have the hope of glory. This mystery was not fully understood or revealed in the Old Testament, but through Christ's life, death, and resurrection, it has been made known to us.
But this mystery is not something that we keep to ourselves. As Christians, we have a responsibility to proclaim it to the world. This is not just a matter of sharing the gospel message with others, but also of teaching and admonishing one another so that we may all grow to maturity in Christ.
This requires wisdom, which Paul says we should use in our teaching and admonishing. We must be sensitive to the needs of those we are ministering to, and discerning about how best to help them take the next step in their journey with Christ.
Ultimately, our mission is to present everyone fully mature in Christ. This is not something that we can accomplish on our own, but through the power of Christ in us, we can be faithful to the task that He has given us. May we always remember the mystery of the gospel and our responsibility to proclaim it to the world, and may we be faithful guides to those who are seeking to grow in their relationship with Christ.