What is Paul’s “mystery” in Ephesians 3 and Colossians 1, and why was it hidden?
Question 009112
Paul uses the word “mystery” in a very specific and technical sense that differs from its ordinary usage. When we speak of mysteries today, we typically mean something puzzling or unknown. Paul’s use of the Greek musterion means something different: not a riddle to be solved by clever reasoning, but a divine secret that was hidden in previous ages and has now been disclosed by God’s own initiative. Understanding what Paul means by the mystery in Ephesians 3 and Colossians 1 is essential for reading those letters rightly, and it carries significant implications for how the relationship between Israel and the Church is understood.
The Meaning of Musterion
The Greek word musterion was used in the ancient world in the context of mystery religions, where it referred to secret rites and knowledge accessible only to initiates. Paul takes the word and redirects it entirely. In his usage, the mystery is not secret knowledge guarded by a religious elite; it is a divine disclosure made known through apostolic proclamation, now open to all. The emphasis falls on the transition from concealment to revelation, not on the complexity of the content.
Ephesians 3:4-6 defines the content with unusual precision: “the mystery of Christ, which was not made known to the sons of men in other generations as it has now been revealed to his holy apostles and prophets by the Spirit.” Paul then states what this mystery actually is: “that the Gentiles are fellow heirs, members of the same body, and partakers of the promise in Christ Jesus through the gospel.” The mystery is not simply that Gentiles would be saved; the Old Testament contains hints of Gentile blessing (Isaiah 49:6; Genesis 12:3). The specific mystery is the nature of their inclusion alongside Jewish believers in one undivided body, sharing equally in every dimension of the inheritance.
The Mystery in Colossians 1
Colossians 1:26-27 approaches the same mystery from a slightly different angle. Paul describes it as “the mystery hidden for ages and generations but now revealed to his saints.” He then gives a compressed but striking definition: “Christ in you, the hope of glory.” This formulation emphasises the indwelling of Christ by the Spirit as the present reality of the new covenant community, a reality now extending to Gentile believers who could not previously have claimed it within the framework of Israel’s covenant life.
The phrase “Christ in you” carries weight precisely because “you” is plural. It is not merely the individual mystical experience of Christ dwelling in each believer’s heart, though that is included; it is the reality that the Gentile believers addressed by Paul are participants in the same indwelling life of Christ as their Jewish brothers and sisters in the faith. One body, one inheritance, one indwelling Spirit, regardless of ethnic or national background.
Why It Had Not Been Previously Disclosed
The question of why the mystery was withheld deserves careful handling, because it is sometimes stated with more bluntness than the texts warrant. Paul does not say the mystery was entirely absent from the Old Testament; he says it was not made known “as it has now been revealed.” There is a distinction between hints, shadows, and anticipations on one side, and the full, explicit disclosure now made on the other.
The Old Testament does speak of Gentile blessing and participation in Israel’s God. But it does not reveal the specific form that participation would take: not as proselytes joining the national life of Israel, but as members of a new entity, the body of Christ, in which the Jew/Gentile distinction, though not erased, is no longer the organising principle of covenant membership. That specific shape was hidden. God had purposes He chose not to disclose until the time of their fulfilment. Ephesians 3:9 speaks of “the plan of the mystery hidden for ages in God who created all things,” indicating that the concealment was deliberate and the disclosure was timed.
This matters enormously for how the Old Testament is read. It guards against the interpretive move of reading the Church back into every Old Testament prophecy and promise addressed to Israel. If the Church was genuinely hidden and not disclosed in previous generations, then those Old Testament texts cannot simply be assumed to describe the Church when they use the language of Israel, land, temple, and throne. The mystery was hidden; it required specific, new apostolic revelation to be disclosed. That does not reduce the Old Testament to irrelevance; it maintains the integrity of both testaments by reading each on its own terms.
So, now what?
Grasping what Paul means by the mystery prevents two equally damaging interpretive errors. Reading the Church back into the Old Testament flattens the distinction between God’s programme for Israel and His programme for the Church, making confusion between the two testaments almost inevitable. Failing to take the mystery seriously, on the other hand, produces a Christianity that cannot account for the astonishing breadth of the gospel’s reach to all nations. The mystery, now disclosed, is Paul’s basis for his entire Gentile mission: Jews and Gentiles together, in one body, in Christ.
“This mystery is that the Gentiles are fellow heirs, members of the same body, and partakers of the promise in Christ Jesus through the gospel.” Ephesians 3:6
