The mystery in Romans 16:25 is the secret doctrine Paul called 'my gospel' — kept secret since the world began and revealed to the Apostle Paul.
Paul writes that God is able to establish believers according to Paul's gospel and the preaching of Jesus Christ, according to the revelation of the mystery which was kept secret since the world began. Les Feldick emphasizes this was something Peter did not know and had not been revealed until Paul received it. It is the body of truth Paul refers to as the Mystery.
Romans 16:25 — This is the verse the question asks about; Paul himself defines the mystery as something kept secret since the world began and now revealed through the preaching of Jesus Christ.
Romans 16:25 says, "Now to him that is of power to stablish you according to my gospel, and the preaching of Jesus Christ, according to the revelation of the mystery, which was kept secret since the world began." Paul describes God's power to establish believers and ties it to three things: Paul's gospel, the preaching of Jesus Christ, and the revelation of a mystery that had been kept secret since the world began. The verse presents the 'mystery' as something hidden until that point and now revealed.
Les Feldick reads Romans 16:25 as one of the plainest statements that Paul was preaching something God had kept completely hidden. He stresses that the Greek word mysterion is translated 'secret,' and Paul says that secret was 'kept secret since the world began.' Les points out that Peter did not know it, and that it had not been revealed before. He calls these revealed secrets basic to all Pauline doctrines.
The verse says God is able to establish believers according to Paul's gospel and the preaching of Jesus Christ, according to the revelation of the mystery which was kept secret since the world began. Paul ties the mystery directly to his own gospel message.
Les explains that the Greek word mysterion is translated 'secret.' A revelation is a revealing of something that had never been revealed before. This secret was kept secret since the world began, and Les notes it was never prophesied in the Old Testament. It is a whole new revelation, not a continuation of something already promised.
Les points out that after his conversion Paul did not go up to Jerusalem to confer with the apostles. Instead, by divine purpose, he went to Arabia — to Mount Sinai — where, based on the account in Acts, he apparently spent about three years. There God began revealing these secrets to this 'renegade Saul of Tarsus.'
Les says Peter did not know it because it had not been revealed yet. He adds that Israel had no concept of these truths and the Twelve had no concept of them either. These truths were not found in the Old Testament, not in Christ's earthly ministry, and not in Peter's activity in the Book of Acts.
Paul Went to Arabia Instead of Jerusalem
Paul did not confer with the twelve apostles but went to Arabia, where Mount Sinai is, and apparently spent about three years there by divine purpose before carrying this revelation.
Romans 16:25 Read Clearly
Les reads Romans 16:25 to show Paul was preaching something God had kept secret since the world began — something Peter did not know because it had not been revealed.
Mysterion Means Secret
Les explains that the Greek word translated 'mystery' is mysterion, meaning 'secret,' and that a revelation is a revealing of something never before revealed.
Secrets Held Until Paul
Les says these secrets were held by God throughout human history and revealed only when He called Paul as the Apostle of the Gentiles; they are basic to all Pauline doctrines.
Colossians 1:25-26 Mystery
Les ties Romans 16:25 to Colossians 1:25-26, where the same mystery is said to have been hid from ages and generations and now made manifest — Israel and the Twelve had no concept of it.
The Secret Kept from the Age Began
Les reads Romans 16:25 carefully and notes the secret was kept from the age began, showing the long-hidden nature of what Paul was revealing.
Never Prophesied
Les emphasizes this mystery was never prophesied; it was a secret kept since the world began, connected to Deuteronomy 29 where secret things belong to God.
The Whole Revealed Body of Truth
Les describes this mystery as part of the whole revealed Body of Truth Paul refers to as the Mystery — not in the Old Testament, not in Christ's ministry, and not in Peter's Acts activity.
Romans 16:25: Now to him that is of power to stablish you according to my gospel, and the preaching of Jesus Christ, according to the revelation of the mystery, which was kept secret since the world began,
This verse is the exact passage in question and defines the mystery as something kept secret since the world began.
Colossians 1:26: Even the mystery which hath been hid from ages and from generations, but now is made manifest to his saints:
Les uses this verse to show the same mystery was hidden from previous ages and generations but is now made manifest.
According to Les Feldick, Peter did not know it because it had not been revealed yet. Israel had no concept of it, and the Twelve had no concept of it either. It was a new revelation given to Paul.
Paul's 'my gospel' refers to the message he preached, which was tied to the preaching of Jesus Christ and the revelation of the mystery kept secret since the world began. It was a body of truth God revealed specifically through Paul.
Les connects them as the same mystery. In Colossians 1:26, it is described as having been hid from ages and generations but now made manifest. Both passages point to a secret revealed to Paul for the Body of Christ.
Watch the Teaching: Why Paul's Gospel Was Different — Galatians 1:11 Explained