One can just read the bible and enjoy the stories. One can really understand scripture by just knowing a few details.
“Context is king.” If one wants to understand, one must understand the context. It is usually ignored to support many church doctrines. Can that word “all” be understood as the churches teach when the context shows the subject is a people who know the Law of God. God put old testament quotes in the new testament for context. The verse can not be properly understood without understanding the context of that original quote.
God defines His own terms in scripture. My list of these includes: Adoption, adultery, glory, covenants, Law, service of God, promises, elect, My or The Called and church. Children, firstborn, chosen, royal priesthood, holy nation, peculiar or special treasure, treasure, grapes, olives, even wild olives and sheep. Afar off and those near. Brother and neighbor. “Not a people” and food. Any verse that contains these words can not be understood without knowing God’s definition for them. There are many clues for one to find. Watch for words in the English, that are entirely different in the Hebrew and Greek such as Jew and Gentile. They are actually Judah, Judaean and Nations.
Be careful not to misunderstand logical statements. Learn what a Contrapositive statement means. Galatians 3:7 and 29 are grossly misunderstood due to not understanding logic.
Galatians 3:7 “Know ye therefore that they which are of faith, the same are the children of Abraham.”
Now the logical Contrapositive.
“If you are not of the children of Abraham, then ye are not they which are of faith.”
Lastly, never spiritualize a verse. One of many is Romans 9:4. Churches teach that all are adopted into the faith. Paul said Israel is adopted or placed. There is no spiritual Israel. The reason that false doctrine was created is due to impostors claiming to be Israel.
Of course most of this makes no sense at all if one has those who are anti-Christ in the roll of God’s chosen.