You must be born again as a new creature. Gen 48 tells the story. Joseph's 2 sons were born Gentile to an Egyptian woman. Joseph's Father was renamed by God to Israel. Jacob loved Joseph's sons so much he adopted The pagan sons so they would have an equal portion of the promised land inheritance. A pagan has no part of the inheritance unless they are adopted into Spiritual Israel. When you are reborn in the Spirit, you are adopted into the Family of God. There is absolutely nothing in Scripture that promises anything to Gentiles. The Jews are God's chosen people. We must be adopted into Jacob's family through the cross. Jacob crossed his hands to bless Ephraim as the first born in Gen 48. You must circumcise your heart to be in God's family.
Now for the Babylon shtick.......Nimrod built the Tower to get to Heaven without God. God stopped him. The Babylon religion was started then to worship many gods. It doesn't matter if the god was named Jupiter for the Romans or Zeus for the Greeks, or any one of many gods for the other kingdoms. The RCC changed the Sabbath and added Christmas, which was Tammuz's birthday and Easter was added for the fertility god Semiramis or Ishtar for Easter. The pope forbid anyone from observing the Feast Days under penalty of death. The RCC hated the Jews. That is called the "Spirit of Antichrist" in Scripture. Nothing Biblical happened on Christmas and Easter. Jesus was born on Tabernacles, died on Passover, was buried on Unleavened Bread, and rose on First Fruits. The church was born on Pentecost with the giving of the Holy Spirit. He will Rapture His church on the Feast of Trumpets and judge them on Atonement and return to rule and reign with His people on Tabernacles. Christmas and Easter are pagan days introduced by the RCC.
As for what Paul said, read Romans 8-9-10 for his teaching on Jews and Gentiles in God's eyes. He explains life in the Spirit. We have become heirs with Christ with future glory promised.
Rom 9:6 But it is not that the word of God has taken no effect. For they are not all Israel who are of Israel,
Rom 9:7 nor are they all children because they are the seed of Abraham; but, "In Isaac your seed shall be called."
Rom 9:8 That is, those who are the children of the flesh, these are not the children of God; but the children of the promise are counted as the seed.
"the children of the promise are counted as the seed" tells us we are adopted in by the Holy Spirit. The "promise" is always the Holy Spirit.
Salvation is from the Jews. Jesus came to us as a Jew. All covenants were to the Jews. The oracles of God were given to the Jews. If you aren't adopted into Israel, you have no part in any inheritance. Anything else is called Babylon in the Bible. The RCC is the Whore of Babylon because she worships idols and other gods. She is dressed in red and purple. She lives on 7 hills and is responsible for killing more saints that all other religions combined. Tear down your statues and stop worshiping Mary and Peter, Paul, and others. Jesus is the only Mediator between God and man, so Mary cannot grant any prayers or hear any prayers. Forgiveness only comes from God. There are no popes in Scripture, no cardinals, no nuns. Scripture tells us forbidding to marry is "doctrines of demons".
Stop looking for denominations to give you the truth. The Truth is a person. Read you Bible.