Romans 16:25-26: “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, But now is made manifest, and by the scriptures of the prophets, according to the commandment of the everlasting God, made known to all nations for the obedience of faith.”
Ephesians 3:1-9: “For this cause I Paul, the prisoner of Jesus Christ for you Gentiles, If ye have heard of the dispensation of the grace of God which is given me to youward: How that by revelation he made known unto me the mystery; (as I wrote afore in few words, Whereby, when ye read, ye may understand my knowledge in the mystery of Christ) Which in other ages was not made known unto the sons of men, as it is now revealed unto his holy apostles and prophets by the Spirit; That the Gentiles should be fellowheirs, and of the same body, and partakers of his promise in Christ by the gospel: Whereof I was made a minister, according to the gift of the grace of God given unto me by the effectual working of his power. Unto me, who am less than the least of all saints, is this grace given, that I should preach among the Gentiles the unsearchable riches of Christ; And to make all men see what is the fellowship of the mystery, which from the beginning of the world hath been hid in God, who created all things by Jesus Christ.”
The Church itself was not a mystery (or secret) prior to Paul, neither was the Gospel, neither was God's great eternal plan of redemption, neither was the ingathering of the Gentiles. Passage after passage in the Old Testament predicted these events. What was a mystery was the Gentiles being “fellowheirs, and of the same body, and partakers of his promise in Christ by the gospel.”
Dispensationalists typically present the New Testament Church as a brand-new spiritual innovation, which had no existence prior to Pentecost. They teach that the Church itself is “the mystery” and that it is a completely separate entity to God’s people in the Old Testament. They say that because the New Testament Church is expressly called ‘the fellowship of the mystery, which from the beginning of the world hath been hid in God’ that it is a brand new construction started at the Upper Room. They contend that the Apostle Paul was specifically and specially tasked with revealing this great mystery.
What they miss is that the Church is not a New Testament novelty introduced by Christ but an ongoing spiritual organism that has contained the elect of God from the very beginning. The Church is not something entirely unique in God's plan and purposes but is an extension of Old Testament believing Israel. Whilst the Church has taken on a different form under the new covenant, in the same way as the development / change occurs between the caterpillar and the butterfly, the elect in the Old Testament and the elect in the New Testament are part of the same spiritual body.
Paul never says that the Church wasn’t about before Pentecost. In fact, he teaches the opposite. He identifies the mystery in a clear and unambiguous way in verse 6, namely: “That the Gentiles should be fellowheirs, and of the same body, and partakers of his promise in Christ by the gospel.” The Dispensational interpretation is the exact opposite to what the inspired text is actually saying. Paul is in fact talking about the joining of the old and new covenant saints together in Christ. The mystery is the mystical union of the people of God of all time in one spiritual body. He is talking about the parity that resulted from this merger in regard to the promises of God.
Thomas Croskery explains on this subject in his classic work from 1879 Plymouth-Brethrenism, a refutation of its principles and doctrines: “Though the prophets foretold that the Gentiles were to be blessed in Abraham, it was not made known to them in what manner the blessing was to be realized. This was the special revelation to which the apostle alludes when he speaks of the dispensation committed to himself as the apostle to the Gentiles.”
He adds: “we, of this dispensation, were to be incorporated into the ‘one commonwealth’, from which we were alienated, into the ‘one body’, the ‘one household’, the ‘one building fitly framed together’. The mystery was the admission of Gentiles to share on equal terms with the Jews all the blessings purchased by Christ.”
