Ephesians 2:11-22 Therefore remember that formerly you, the Gentiles in the flesh, who are called “Uncircumcision” by the so-called “Circumcision,” which is performed in the flesh by human hands— remember that you were at that time separate from Christ, excluded from the commonwealth of Israel, and strangers to the covenants of promise, having no hope and without God in the world. But now in Christ Jesus you who formerly were far off have been brought near by the blood of Christ. For He Himself is our peace, who made both groups into one and broke down the barrier of the dividing wall, by abolishing in His flesh the enmity, which is the Law of commandments contained in ordinances, so that in Himself He might make the two into one new man, thus establishing peace, and might reconcile them both in one body to God through the cross, by it having put to death the enmity. And He came and preached peace to you who were far away, and peace to those who were near; for through Him we both have our access in one Spirit to the Father. So then you are no longer strangers and aliens, but you are fellow citizens with the saints, and are of God’s household, having been built on the foundation of the apostles and prophets, Christ Jesus Himself being the corner stone, in whom the whole building, being fitted together, is growing into a holy temple in the Lord, in whom you also are being built together into a dwelling of God in the Spirit.
We’re the disciples taught anything about this?
14 “I am the good shepherd, and I know My own and My own know Me, 15 even as the Father knows Me and I know the Father; and I lay down My life for the sheep. 16 “I have other sheep, which are not of this fold; I must bring them also, and they will hear My voice; and they will become one flock [with] one shepherd. (NASB1995)
Not only did Jesus tell them that He was dying for more than just Israel’s sheep, but for us as well, and they understood this.
John 11:49 But one of them, Caiaphas, who was high priest that year, said to them, “You know nothing at all, 50 nor do you take into account that it is expedient for you that one man die for the people, and that the whole nation not perish.” 51 Now he did not say this on his own initiative, but being high priest that year, he prophesied that Jesus was going to die for the nation, 52 and not for the nation only, but in order that He might also gather together into one the children of God who are scattered abroad. (NASB1995)
Yes, the apostles knew, just as Paul had explained in Ephesians that we are one in Christ, So John knew that to be the reason for Jesus dying. Jesus did not segregate His sheep into two pens. He died for both Jew and Gentile one new man.
To divide the Gentile Church from Israel is not Scriptural.