Ephesians is Paul's Epistle testifying that God Himself has built His Church. God wanted to adopt all human beings as His children and let them dwell in His Church. As the way to achieve that, He spoke of the salvation that is received through the Gospel.

In the Book of Ephesians, Paul explained the process in which God's children have come into existence. Ephesians 1:3, "Blessed be the God and Father of our Lord Jesus Christ, who has blessed us with every spiritual blessing in the heavenly places in Christ." This means that God the Father had planned to make us His own children through the Gospel found in Jesus Christ His Son.

We should realize first of all that every spiritual blessing  that the saints receive comes to them through their faith in the Gospel, because the Father had already planned to make us His own children in Jesus Christ. And when the time came He completed our salvation in Jesus as the True Gospel, The work of  the Father and Jesus lacked nothing to fulfill His will.