3:1 For this cause I, Paul, am the prisoner of Christ Jesus on behalf of you Gentiles,

3:2 if it is so that you have heard of the administration
of that grace of God which was given me toward you;
3:3 how that by revelation the mystery was made known to me,

as I wrote before in few words,
3:4 by which, when you read,
you can perceive my understanding in the mystery of Christ;
3:5 which in other generations was not made known to the children of men, as it has now been revealed to his holy apostles and prophets in the Spirit;
3:6 that the Gentiles are fellow heirs, and fellow members of the body,
and fellow partakers of his promise in Christ Jesus through the gospel,

3:7 whereof I was made a servant,
according to the gift of that grace of God
which was given me according to the working of his power.

3:8 To me, the very least of all saints, was this grace given,

to preach to the Gentiles the unsearchable riches of Christ,
3:9 and to make all men see what is the administration of the mystery
which for ages has been hidden in God, who created all things through Jesus Christ;
{TR reads "fellowship" instead of "administration"}

3:10 to the intent that now through the assembly the manifold wisdom of God
might be made known to the principalities and the powers in the heavenly places,

3:11 according to the eternal purpose which he purposed in Christ Jesus our Lord;

3:12 in whom we have boldness and access in confidence through our faith in him.

3:13 Therefore I ask that you may not lose heart at my troubles for you, which are your glory.

There is nothing more worthwhile in the long run than ministering the gospel of God's grace. "Therefore, since through God’s mercy we have this ministry, we do not lose heart." 2Cor 4:1 and "Consider him who endured such opposition from sinful men, so that you will not grow weary and lose heart." Heb 12:3

Eph 3:1,2  For this reason I, Paul, the prisoner of Christ Jesus for the sake of you Gentiles—  Surely you have heard about the administration of God’s grace that was given to me for you

Here Paul is about to pray again for the Ephesians, but he stops suddenly and digresses concerning the significance of this ministry of grace and the mystery revealed through it. He finishes this digression in verse 13 and picks up his prayer in verse 14 starting again "For this reason I kneel before the Father ..."

Paul has a special role, as the apostle to the Gentiles, as he says in Titus, "At his appointed season he brought his word to light through the preaching entrusted to me by the command of God our Savior" Titus 1:3

Eph 3:3,4 that by revelation there was made known to me the mystery, as I wrote before in brief. By referring to this, when you read you can understand my insight into the mystery of Christ

The writing likely refers to the first couple of chapters of Ephesians. The mystery, of which he also alluded to in Eph 1:9 "he made known to us the mystery of his will", is apparently something which had not been obvious to the Jews but required making an inference - a revelation of the implications of the Word of God directed by the Spirit of God. Such a spirit of revelation as he experienced is something Paul desires for all believers as he prayed in Eph 1:17 "that the God of our Lord Jesus Christ, the Father of glory, may give to you a spirit of wisdom and revelation in the knowledge of him"

Eph 3:5,6 (the mystery) which was not made known to men in other generations as it has now been revealed by the Spirit to God’s holy apostles and prophets. This mystery is that through the gospel the Gentiles are heirs together with Israel, members together of one body, and sharers together in the promise in Christ Jesus.

There are a number of mysteries revealed in the gospels. This is one of them. Namely that all who believe in Christ, regardless of ethnic background, are included in the promise of salvation which formerly had thought to have been exclusive to the Jews. Likewise Paul says to the Colossians, "This mystery that has been kept hidden for ages and generations, but is now disclosed to the saints. 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." Col 1:26,27

Peter preached, "Repent and be baptized, every one of you, in the name of Jesus Christ for the forgiveness of your sins. And you will receive the gift of the Holy Spirit. The promise is for you and your children and for all who are far off— for all whom the Lord our God will call." Acts 2:38,39 But it wasn't until Acts chapter 10 when Peter came to the revelation that this applied to Gentiles as well.

This may not seem so significant these days where it's taken for granted that the gospel applies to non-Jews. In fact today there are denominations which question whether the gospel applies to Jews (which is pretty silly given that all the earliest Christians - indeed the first Christian church - was composed exclusively of Jews). But at the time this was a significant revelation. Jews, even the godly, even the apostles early on, had developed an exclusivist attitude towards Gentiles. But Christ, the Jewish Messiah, came not only to save Jews but the Gentiles as well. "He is the atoning sacrifice for our sins, and not only for ours but also for the sins of the whole world." 1John 2:2

Eph 3:7-9 I became a servant of this gospel by the gift of God’s grace given me through the working of his power. Although I am less than the least of all God’s people, this grace was given me: to preach to the Gentiles the unsearchable riches of Christ, and to make plain to everyone the administration of this mystery, which for ages past was kept hidden in God, who created all things.

Likewise Paul writes, "I am the least of the apostles and do not even deserve to be called an apostle, because I persecuted the church of God.  But by the grace of God I am what I am, and his grace to me was not without effect. No, I worked harder than all of them— yet not I, but the grace of God that was with me." 1Cor 15:9,10

Indeed in chosing Paul God revealed another mystery - namely the extent of His grace. Paul writes, "The grace of our Lord was poured out on me abundantly, along with the faith and love that are in Christ Jesus. Here is a trustworthy saying that deserves full acceptance: Christ Jesus came into the world to save sinners— of whom I am the worst.  But for that very reason I was shown mercy so that in me, the worst of sinners, Christ Jesus might display his unlimited patience as an example for those who would believe on him and receive eternal life." 1Tim 1:14-16

God's messenger himself is part of the message. Are you least enough to share God's message?

As for the intensity of his labor in comparison to others, I'm reminded of Jesus' parable of the Two Debtors.

Eph 3:10-11 His intent was that now, through the church, the manifold wisdom of God should be made known to the rulers and authorities in the heavenly realms, according to his eternal purpose which he accomplished in Christ Jesus our Lord.

How do the angels - whether they be fallen like the devil or heavenly - learn more about God? One way is through his interaction with mankind. In this case it is through the body of believers - the Christian community - that angels are learning more about God.

Eph 6:12  For our struggle is not against flesh and blood, but against the rulers, against the authorities, against the powers of this dark world and against the spiritual forces of evil in the heavenly realms.

Through the church the angels are learning about God's grace - the depth and the extent of God's gracious nature. Jesus said that the eternal fire (had been) prepared for the devil and his angels. Mt 25:41 It is through the condemnation of hell fire, being the fate of fallen angels, that God revealed his judicial nature. But through mankind, and in particular through the Christian community, his intention was to reveal his gracious nature.

All people will glorify God. Either they will end up glorifying his judicial nature or his gracious nature. Which would you prefer?

Eph 3:12-13  In him and through faith in him we may approach God with freedom and confidence. I ask you, therefore, not to be discouraged because of my sufferings for you, which are your glory.

God is ordinarily not approachable. He is "dwelling in unapproachable light." 1Tim 6:16 But "you have not come to the mountain that may be touched and that burned with fire, and to blackness and darkness and tempest,  and the sound of a trumpet and the voice of words, so that those who heard it begged that the word should not be spoken to them anymore.  (For they could not endure what was commanded: "And if so much as a beast touches the mountain, it shall be stoned or shot with an arrow." And so terrifying was the sight that Moses said, "I am exceedingly afraid and trembling.") Through Christ's atoning work, and through faith in him we can approach God confidently both now and on the judgement day.

"Let us therefore come boldly to the throne of grace, that we may obtain mercy and find grace to help in time of need." Heb 4:16