I do not believe you disagree with me concerning Gentile Christians. I believe you don't understand that God talks to different people in the Bible. When He's writing about Jews He's not writing about Christians. When He's writing about Christians He's not writing about Gentiles. You believe God is writing to everyone and so you don't understand what I'm saying.
The entire NT Scriptures speak of the transition from Jewish Religion to the Christian Religion, which largely consisted of Gentiles. The Bible uses the term "Gentile" and the Bible uses the term "Christian." It doesn't have to use it in the exact order "Gentile Christian" to imply that very thing.
When the Bible notes that someone is not a Jew, it is often speaking of a Gentile. And when that Gentile converts to Christianity he has become, logically, a Gentile Christian.
The term "Gentiles" comes from the Jewish sense of "nations," which was the main object of God's promise to Abraham. He began with Israel, but He planned to advance into the Gentile world through conversion to what had begun with Israel.
In fact, the term for "nations" can be attributed to Jews who had migrated there, or who had ended up there in the diasporas. They would not, technically, be called "Gentiles" today, but it's basically the same word (see Acts 2).
So what we're really speaking of when we say "Gentile Christians" is the conversion of the nations to Christianity, which had begun after the death of Jesus. To say this idea or terminology didn't exist in the Bible is wrong, in my opinion.
Rom 4.13 It was not through the law that Abraham and his offspring received the promise that he would be heir of the world, but through the righteousness that comes by faith.
Gal 3.8 Scripture foresaw that God would justify the Gentiles by faith, and announced the gospel in advance to Abraham: “All nations will be blessed through you.”
I do not know why we have so many Christians who believe the entire Bible is written directly to them, the Church of God. There is nothing in the Bible to indicate such thinking, and I would like to add nothing could be further from the truth. It's true the Word of God was written for everyone for all time, and it's for our learning because it contains what everyone should know. That does not mean every part of it is addressed to everyone in this time, because the subject matter was written either to the Jews, to the Gentiles, or to the Church of God (1 Corinthians 10:32).
These kinds of statements can easily be misconstrued. Was the Bible predetermined by God to be for the Church? Of course.
Were all the epistles and gospel written for specific groups at certain times or were they written more broadly for any future generations? I would have to say that some parts of the Bible had certain groups in mind but were of such quality that God determined in advance that they could also be used for future generations.
Some books were evidently given for any group of Christians for any future generation. It does help to know if there is a specific group being referenced in any particular work.
For example, 1 Peter seems addressed to Jewish believers. The book of Revelation was written to 7 churches of Asia Minor. Philemon was written to Philemon, Romans to Roman Christians, etc. But the historic Church has seen fit to include them in the "Christian Scriptures," recognizing their universal value and apostolic authority. God obviously knew this could and perhaps would happen.
To rightly understand the Word of God, one must understand what part is written to the Church of God and what part is written for the learning of the Church. Every word from Genesis 1:1, to Revelation 22:21, is written for our learning. However, not all of the words from Genesis 1:1, to Revelation 22:21, are addressed to us. We must learn to distinguish not only the various people, but also the different time periods God has spoken to if we want to understand the written Word of God. The time God spoke to the children of Israel is not the same time period He has spoken to us. The time He spoke to the prophets in the time of the Old Testament is not the same time period He spoke to His Son Jesus Christ in the time of the gospels.
Well, of course. The OT spoke of the era of the Law. The NT starts with the Gospel of Christ, which began in Jesus' ministry while he was still under the Law. The NT epistles and Revelation speak to the Christian Church. These things are obvious.
But I agree that it is important to know what covenant is in the background of many Scripture authors. The Law had a different code to live by than the NT Gospel. So when we read the OT Scriptures and the Gospels we should keep in mind that the Law was still in effect, and that a new set of rules come into play in the NT era.