There is no' Body ' until Acts ..The new testament doesn't begin until Jesus death . And the first Gentile to start the Jew / gentile programme is Cornelius. Which is 10 years after Acts 2 .
Prior to Paul being given the mystery its not known prior .
Eph 3
1¶For this cause I Paul, the prisoner of Jesus Christ for YOU GENTILES ,
2If ye have heard of the DISPENSATION OF THE GRACE OF GOD which is GIVEN ME to you-ward:
3How that by revelation he made known UNTO ME THE MYSTERY ; (as I wrote afore in few words,
4Whereby, when ye read, ye may understand my knowledge in the mystery of Christ)
5Which 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;
6THAT THE GENTILES SHOULD BE FELLOWHEIRS AND OF THE SAME BODY ,AND PARTAKERS OF HIS PROMISE IN CHRIST BY THE GOSPEL :
1 cor 12
13For by one Spirit are we all baptized into one body, whether we be Jews or Gentiles, whether we be bond or free; and have been all made to drink into one Spirit.