Ephesians 3:1 For this cause I Paul, the prisoner of Jesus Christ for you Gentiles, 3:2 If ye have heard of the dispensation of the grace of God which is given me to you-ward: 3:3 How that by revelation he made known unto me the mystery; (as I wrote afore in few words, 3:4 Whereby, when ye read, ye may understand my knowledge in the mystery of Christ) 3:5 Which in other ages was not made known unto the sons of men, as it is now revealed unto his holy apostles and prophets by the Spirit; effectual working of his power.
Far more than being only about circumcision or racism, Paul is explaining the mystery of the doctrine of salvation by Jesus Christ in this Epistle.
3:6 That the gentiles should be fellow heirs and of the same body, [that is, the same body (Ekklesia) of Christ], that they should all be made one in Christ [The faithful are to be in complete unity with God the Father and Jesus Christ, and therefore in unity with each other.] and partakers of his promise in Christ by the gospel
The true gospel is the gospel of salvation through sincere repentance, the application of the sacrifice of Christ the Lamb of God a dedicated zeal to learn and to keep the whole Word of God and complete unity with Christ and with God the Father; which brings the promise of a resurrection to spirit and eternal life.
3:7 whereof I [Paul] was made a minister according to the gift of the grace of God, given unto me by the official working of his power.
Paul was called by God in God’s mercy, just as we were also called out of sin to come to God the Father through Christ, and to follow the Father in Christ-like zeal to live by every Word of God.
3:8 Unto me, whom am less than the least of all saints, is this grace given that I should preach among the gentiles the unsearchable riches [the doctrine of salvation] of Christ. 3:9 And, to make all men see what is the fellowship of the mystery which from the beginning of the world hath bee hid in God who created all things by Jesus Christ.
Paul said that God created all things by the one who became Jesus Christ. Jesus Christ created all things and was the very Implementing Creator fulfilling the plan of God the Father.
3:10 To the intent that now unto the principalities and powers in heavenly places might be known by the church [the called out Ekklesia] the manifold wisdom of God, 3:11 According to the eternal purpose which he purposed in Christ Jesus our Lord: 3:12 In whom we have boldness and access with confidence by the faith of him.
Paul was called to make known the mystery of the purpose and the plan of God and the mystery of the true doctrine of salvation.
The faithfully obedient to our heavenly Father have access to God the Father with boldness and confidence; knowing that we are not accessing the Father to encounter wrath and fury over our past disobedience.
Knowing that our past disobedience has been sincerely repented of and atoned for and has been forgiven; and that God the Father loves us so much that he gave his Son for us; we can approach God our Father boldly and have access to Him with confidence by the faith of God.
3:13 Wherefore, I desire that ye faint not at my tribulations and my troubles, for you, which is your glory.
Paul says, do not be upset or offended over my sufferings which are for your good [I suffer to preach to you the gospel of salvation that you might be glorified],
3:14 for this cause I bow my knees unto the Father of our Lord Jesus Christ 3:15 of whom the whole family [that is, the body of Christ, the family of God] in heaven and earth is named, 3:16 That he would grant you according to the riches of his glory to be strengthened with might by his spirit in the inner man.
Paul prayed as we all should, that God would deliver the people out of sin and into godliness and grant them his Spirit and eternal salvation.
3:17 That Christ [through the Holy Spirit] may dwell in your hearts by faith [belief in the whole Word of God combined with the works of faith], that ye be rooted and grounded in love [which is obedience to God], 3:18 may be able to comprehend, to understand, with all saints what is the breadth, the length, and depth and height. 3:19 And to know the love of Christ which passes knowledge that ye might be filled with all the fullness of God [so that we can all become just like God the Father].
3:20 Now, unto him that is able to do exceedingly, abundantly above all that we ask or think, according to the power [the power of God’s Holy Spirit which is in those who are dedicated and passionately obedient to the whole Word of God] that works in us, 3:21 unto him be glory in the church by Christ Jesus, throughout all ages, world without end. Amen.
Paul is hoping and praying. and encouraging the called out; so that they will understand and fully comprehend the tremendous love that Christ had and has, to give himself for all people and not just his own brethren in Judah for he was born of the flesh of Judah, but for all mankind, for the Gentiles and all humanity.
Paul wants us to begin to comprehend and to understand the breadth, the length, the depth, and the height of the love of Christ who gave himself for all peoples; and to understand the love of God the Father who gave his only son, his only begotten son, for all humanity. In the hope that when we understand the tremendous love that Jesus Christ and God the Father have for us, we will reciprocate that love and follow the Mighty Ones of our Salvation to dedicatedly love them and passionately desire to be like them; hungering and thirsting to internalize their nature, by keeping their Words of Life eternal.