“For the sake of this, I, Paul, the prisoner of Christ Jesus for you gentiles, if indeed you heard of the stewardship of the grace of God that was given to me for you, that according to revelation the mystery was made known to me, just as I wrote formerly in brief.”
There are a few points in these verses that need some highlighting. For instance, while we know that Paul was most likely writing this letter from prison, you will notice the Paul does not write that he is a prisoner of Rome. No, Paul writes that he is a prisoner of Christ Jesus for the sake of the gentiles. Ultimately, Rome has no control over the person or the body of Paul. Jesus does. Whether Paul lives or dies, it is for the Lord’s glory, as he would write to the church in Philipi. How is it that Paul is in prison for the Gentiles? It is God’s calling on his life to evangelize the Gentile people, just as Peter is the Apostle to the Jewish church (Galatians 2:7-8). Thus, he is a prisoner of Jesus, a captive of the Gospel and commissioned to take that Gospel to the gentile churches to the praise of God.
The stewardship that Paul speaks of here is a reference then to the Gospel of Grace of which Paul has just previously spoken. As Ephesus is a dominantly Gentile church, Paul clearly writes that this Gospel was given to them. And, how did Paul receive this Gospel? He received it by revelation, as he records in Galatians 1:11-17.
Why is this called a mystery? The question of how God was going to redeem his elect from amongst the nations was veiled in the Old Testament and fully revealed in Christ. Paul’s job is to reveal to those who will listen, that which has been formerly hidden. What is this that Paul wrote formerly? It seems as if there was an earlier letter that Paul addressed to this church, which the Holy Spirit has not preserved for the church. This reference likely should not be understood as the words earlier found in this chapter, as some commentators suggest, for προγράφω (prographo — “to write in advance”) commonly carries with it a chronological sense.
If there is a former letter written to Ephesus, why is that not Canon? If we ever found it, would it become Canon? The answer to the first is one that belongs to the Holy Spirit. He did not preserve it and as such, we can infer that this former letter was not inspired. As it was not inspired, even were it to be found, it would not be part of the Canon of Scripture. There is a principle here, which the church has long held and understood. God has preserved his Word through the church as he intended it. Nothing can be added, nor anything taken away. It is God’s gift to the church through the Spirit.