Glad you asked.

The New Testament reading in church this past Sunday was Ephesians 3:1-12. What struck me was how the author (Paul or a later follower of his) speaks of his commission to preach the gospel to Gentiles.

And he keeps using the word “mystery.”

He says in verses 3-6,

The mystery was made known to me by revelation, as I wrote above in a few words, a reading of which will enable you to perceive my understanding of the mystery of Christ. In former generations this mystery was not made known to humankind, as it has now been revealed to his holy apostles and prophets by the Spirit: that is, the Gentiles have become fellow heirs, members of the same body, and sharers in the promise in Christ Jesus through the gospel.

In verses 8-9 he adds,

Although I am the very least of all the saints, this grace was given to me to bring to the Gentiles the news of the boundless riches of Christ, and to make everyone see what is the plan of the mystery hidden for ages in [or by] God who created all things. . . .

We see a similar vibe in Romans 16:25-27:

Now to God who is able to strengthen you according to my gospel and the proclamation of Jesus Christ, according to the revelation of the mystery that was kept secret for long ages but is now disclosed, and through the prophetic writings is made known to all the Gentiles, according to the command of the eternal God, to bring about the obedience of faith—to the only wise God, through Jesus Christ, to whom be the glory forever! Amen.

The letters of Paul use the word “mystery” in more than one way, to be sure. But as I said this reading in Ephesians got me thinking about how the connection between the gospel and the story of Israel (aka the Old Testament, First Testament, Tanak, etc.) isn’t obvious.

I see four things here worth noting:

The “mystery of Christ” is specifically the inclusion of the Gentiles as “fellow heirs” (along with Jews). It’s called a mystery because “in former generations [it] was not made known to humankind,” was “hidden for ages in [or by] God,” and “kept secret for long ages but is now disclosed.” The disclosure of the mystery now in Paul’s day is “by revelation . . . . now . . . revealed to his holy apostles and prophets by the Spirit.” [“Prophets” doesn’t mean Old Testament prophets but prophets of the early Jesus movement. See Ephesians 2:20.] Though a mystery that had to be revealed, the inclusion of the Gentiles is also “in accordance with the eternal purpose [of God] (Ephesians 3:11) and “through the prophetic writings is made known to all the Gentiles” (Romans 16:26).

So I draw two conclusions from all this:

Gentiles as “fellow heirs” with Jews wasn’t known until it was revealed to Paul (and others, perhaps)—in other words, it’s not something you’d “get” from reading the Old Testament on its own terms. This mystery of Gentile inclusion has, nevertheless, been part of God’s purposes since forever, which is now made known “through the prophetic writings.”

God’s eternal purpose for Gentile inclusion isn’t something that jumps out at you from the pages of the Old Testament.

It is hidden. Exegesis won’t get you there. Only revelation will. And once revealed, that which was a mystery “in former generations” is now understood.

This creates a delightful theological tension that, in my view, goes a long way to explaining the creative way Paul engages his scripture:

His task is to explain this revelation of “the mystery of Christ” through the writings of the “former generations,” of those to whom the revelation was “hidden” and “kept secret.”

And so when we watch Paul handling his Bible to speak to this mystery, we can understand why he has to do so in ways that would not have made sense to those of “former generations” to whom the mystery had not been revealed.

This is why we see so much creative license taken by Paul when he calls upon his Bible to speak of Christ. He is looking not to the words in their plain sense to reveal the mystery. Then it wouldn’t be a mystery and wouldn’t need to be revealed.

Rather, Paul’s reading of his Bible has to pull back the curtain to reveal about the behind-the-scenes activity of God, which he only knows because it was disclosed.

Paul, having received the revelation of the mystery, now goes about reading his scripture in a way he never would have imagined before. The revelation of the mystery becomes the lens through which Paul re-encounters his sacred tradition.