“he made known to us the mystery of his will according to his good pleasure, which he purposed in Christ, to be put into effect when the times reach their fulfillment—to bring unity to all things in heaven and on earth under Christ.” Ephesians 1:9-10
Paul's letter to Ephesus, which may not have been written directly by Paul, provides an apology for the Church as the Body of Christ. More specifically, these words are related to redemption through Christ. Jesus was the lamb, sent as a sacrifice so that we may live righteously.
Note the call to unity to all. We are not the same as each other, but we are to cooperate under Christ, as He purposed.