6 that the Gentiles should be fellow heirs, of the same body, and partakers of His promise in Christ through the gospel,
Paul now defined the “mystery.” The central idea is that both Jew and Gentile are fellow heirs in the new economy or the dispensation of grace. Three descriptions depict this new entity:
Jews and Gentiles are “fellow heirs” in the church.
They are fellow members “of the same body.”
They are “partakers of the promise in Christ.”
6 that the Gentiles should be fellow heirs,
This verse repeats the word “together” in the Greek three times: “heirs together,” “members together of one body,” and “sharers together in the promise in Christ Jesus.” Gentiles and Jews belong jointly to the same body.
First, Jew and Gentile are “fellow heirs.” The implication is that as “heirs” we inherit certain possessions. The phrase following “that” is not a purpose clause but a statement of fact. The Gentiles are, in fact, fellow heirs with Jews. An “heir” here refers to all that someone receives in salvation. All believers jointly possess an inheritance with Christ.
Gentiles were to be fellow heirs with Jews in the church. This was a groundbreaking idea. Ephesian Gentiles were no longer “strangers and aliens,” but now they received an inheritance with God (1:3, 11,14, 18; Ga 3:29).
Gentiles are “fellow heirs” because they are joint-heirs with Christ and the Jews by regeneration (Ro 8:17). This happens by placement into the body called the church.
of the same body,
Second, Jew and Gentiles are “of the same body.” Gentiles are no longer outsiders but hold the same benefits as Jews in the new economy. They are fully privileged before God. Both Jew and Gentile hold the same standing before God in Christ.
Gentiles are full-fledged members of the body of Christ. In no sense are they second-class citizens in the church (1 Co 12:12-13). The “mystery” then is the complete union of both Jew and Gentile into the “same body,” that is, their eternal status “in Christ.”
Both Jews and Gentiles are members of the same unitary, corporate body called the church (2:15). The church as one body has only one head.
and partakers [sharers together] of His promise in Christ
The third of three privileges Jew and Gentile share together is the “promise in Christ.” The promise here is singular. Believers partake of the one promise of being “in Christ.” “In Christ” refers to our status with Christ before God; it is our positional status with God forever.
It was no mystery that Gentiles would be saved. They were saved in the Old Testament. The mystery is there is a new body, the church, where both Jew and Gentile hold the same status in Christ.
The “promise” here is the promise of giving the indwelling Holy Spirit to each believer and to the church.
through the gospel,
The gospel made possible that believing Jews and Gentiles could be placed into “the same body.”
The three privileges of this verse are unique to the church.
The “mystery” is not mysterious but something not hitherto revealed. The idea of the church was a mystery in the Old Testament. The church did not exist during the economy of the law or the nation of Israel; it is an entirely new entity to the New Testament.
None of the three privileges of verse six was true under Israel. Israel and the church are not the same. In the Old Testament, Israel held distinct privilege before God. Israel was a national entity; the church is an organism and not an organization. God did not launch the church until the day of Pentecost (Acts 2). He formed the church by the baptism of the Holy Spirit (1 Co 12:13). That fact makes the church unique.