One of the main matters that the letter to the Ephesians is addressing is the unity of the Body of Christ aka the New Man and The Temple Made Without Hands (made of Living Stones). He is showing that Jewish and gentile Christians are not divided but are one. They are on equal footing. The Jew/gentile dividing wall which existed in the physical Temple does not exist in the New Creation.
So in Ephesians 4, he's saying that there is not one faith for Jews and one for gentiles but they both share the single faith in the one single God (which Paul identifies as the Father). IE: Jewish monotheism and Christian monotheism are identical:
[Ephesians 4:1-6 NASB20] (1) Therefore I, the prisoner of the Lord, urge you to walk in a manner worthy of the calling with which you have been called, (2) with all humility and gentleness, with patience, bearing with one another in love, (3) being diligent to keep the unity of the Spirit in the bond of peace. (4) [There is] one body and one Spirit, just as you also were called in one hope of your calling; (5) one Lord, one faith, one baptism, (6) one God and Father of all who is over all and through all and in all.
So this passage is the antidote to the lies of:
* Dispensationalism's two hopes
* Jehovah's Witnesses' two hopes
* Messianic Judaism (because in the New Man, Jewishness no longer exists)
* the two-Messiahs theory
* the idea of three equal Gods
* any of the other invented bases of unity, such as Sabbath observance, eschatology, etc.
* water baptism in the Christian age
* those who cause division on any of these points
Amen! Unity is essential in the one faith sir. How many faiths does that narrow it down to to you?