Jesus told a Samaritan woman, “Ye worship ye know not what: we know what we worship: for salvation is of the Jews” (Jhn 4:22). The Jewish people know the God they worship because He revealed Himself to them and only to them. Therefore, only they had been given the hope of salvation and eternal life through knowing Him and His Son Jesus Christ, “And this is life eternal, that they might know thee the only true God, and Jesus Christ, whom thou hast sent” (Jhn 17:3).
The correct view of God is the revelation of Himself to His people Israel: “Thou shalt have no other gods before me” (Exo 20:3), “Hear, O Israel: The LORD our God is one LORD” (Deu 6:4). And God’s Son affirmed it, “The first of all the commandments is, Hear, O Israel; The Lord our God is one Lord” (Mar 12:29). There is only one true God, “thee the only true God” (Jhn 17:3), the God of Israel.
Writing to the Gentiles at Ephesus, Paul revealed the mystery hidden from the beginning that God would choose a people, “According as he hath chosen us in him before the foundation [casting down] of the world” (1:4). Figuratively, Adam is Christ and his wife is God’s people. They were given first opportunity to trust in Jesus as their Messiah, “who first trusted in Christ [Messiah]. In whom ye also trusted” (1:12-13). And God’s chosen people are saved by Him favoring them in sending His Son to die for their sins, “Even when we were dead in sins, hath quickened us together with Christ, (by grace [favor] ye are saved;) … For by grace [favor] are ye saved through faith [faithfulness]; and that not of yourselves: it is the gift of God” (2:5,8). Though Gentiles had long been without God, they can now be joined with Israel and saved through Christ, “That at that time ye were without Christ, being aliens from the commonwealth of Israel, and strangers from the covenants of promise, having no hope, and without God in the world … Now therefore ye are no more strangers and foreigners, but fellowcitizens with the saints, and of the household of God” (2:12,19).
Salvation came to all nations of people through one nation of people. Salvation is in the promise made to Abraham and fulfilled through his lineage in one specific Seed or Descendant, Jesus Christ: “and in thee shall all families of the earth be blessed” (Gen 12:3); “thou shalt be a father of many nations” (Gen 17:4); “And in thy seed shall all the nations of the earth be blessed” (Gen 22:18); “to the end the promise might be sure to all the seed; not to that only which is of the law, but to that also which is of the faith of Abraham; who is the father of us all” (Rom 4:16); “That the blessing of Abraham might come on the Gentiles through Jesus Christ; that we might receive the promise of the Spirit through faith” (Gal 3:14); “Now to Abraham and his seed were the promises made. He saith not, And to seeds, as of many; but as of one, And to thy seed, which is Christ.” (Gal 3:16); “And if ye be Christ’s, then are ye Abraham’s seed, and heirs according to the promise” (Gal 3:29).
Both the Old and New Covenants were made with Israel, “Behold, the days come, saith the LORD, that I will make a new covenant with the house of Israel, and with the house of Judah” (Jer 31:31; Heb 8:8), “Who are Israelites; to whom pertaineth the adoption, and the glory, and the covenants, and the giving of the law, and the service of God, and the promises; Whose are the fathers, and of whom as concerning the flesh Christ came, who is over all, God blessed for ever. Amen.” (Rom 9:4-5). Christ took of the bread and wine with His Jewish disciples, then shed His blood to ratify the New Covenant, “For this is my blood of the new testament [covenant], which is shed for many for the remission of sins” (Mat 26:28).
The apostle Paul served the God of his fathers: “The God of Abraham, and of Isaac, and of Jacob, the God of our fathers, hath glorified his Son Jesus” (Act 3:13); “The God of our fathers raised up Jesus” (Act 5:30); “so worship I the God of my fathers, believing all things which are written in the law and in the prophets” (Act 24:14); “I thank God, whom I serve from my forefathers with pure conscience” (2Ti 1:3).
Gentiles are saved by partaking with the Jews in their covenant: “and thou, being a wild olive tree, wert graffed in among them” (Rom 11:17); “Rejoice, ye Gentiles, with his people” (Rom 15:10); “For if the Gentiles have been made partakers of their spiritual things” (Rom 15:27); “who first trusted in Christ [Messiah]. In whom ye also trusted” (Eph 1:12-13); “That the Gentiles should be fellowheirs, and of the same body, and partakers of his promise in Christ by the gospel” (Eph 3:6); “made us meet to be partakers of the inheritance of the saints in light” (Col 1:12).
Salvation isn’t by worshipping the Trinity of the Gentiles but the God of the Jews: “we know what we worship: for salvation is of the Jews … the true worshippers shall worship the Father in spirit and in truth: for the Father seeketh such to worship him” (Jhn 4:22,23); “so worship I the God of my fathers” (Act 24:14).