God doesn't speak of a remnant of mankind, only a remnant of Israel, as seen when God speaks to Elijah.Remnant simply means a few, not all, of anything.
It is not an exclusive term used only for the people of God.
However, it is a Biblical fact, God saves only a remnant of mankind.
God does not say that. It was for unbelief/rejection of the gospel that the nation was PARTIALLY hardened/blinded until the fullness of the Gentiles comes in. God's people were not replaced, but removed. God clearly states through Paul that if they go from unbelief to belief, they are right back in the olive tree. So... not replaced. God further goes on to say he would be more than happy to rip the Gentiles out for not continuing in belief. There is no talk about putting them back in.Which the NT shows rejected and murdered their Messiah, for which the nation was hardened in unbelief and cut off as God's people, being replaced with Gentiles ( Ro 11:16-23).
The Bible does not speak of it this way. Even for Israel, we speak of remnant because that is what God said to Elijah.They don't need to have that for the feet-on-the-ground fact that only a remnant of mankind is being saved.
Consider this part of Romans 11:There are not two tracks for God's people in NT apostolic teaching, there is only one. Salvation is by faith in and trust on the atoning work (blood, Ro 3:25) and person of Jesus Christ for the remission of one's sin and right standing with God. There is no other way to be saved from God's wrath (Ro 5:9) on your sin.
Track two is simply the unbelievers.
"28 [h]From the standpoint of the gospel they are enemies for your sake, but [i]from the standpoint of God’s choice they are beloved for the sake of the fathers; 29 for the gifts and the calling of God are irrevocable. 30 For just as you once were disobedient to God, but now have been shown mercy because of their disobedience, 31 so these also now have been disobedient, that because of the mercy shown to you they also may now be shown mercy. 32 For God has shut up all in disobedience so that He may show mercy to all."
So, according to this, the Gentiles were disobedient, but have been shown mercy because of Israels disobedience. So Israel which now have been (present perfect), can now be shown (future perfect) mercy because the Gentiles had been shown mercy. So two tracks. However, Paul is clear to state that it was all one program. "For God has shut up ALL in disobedience so that He may show mercy to ALL." God handled it one after the other. The Gentiles were disobedient, but because Israel was disobedient, God showed mercy to the Gentiles. Because God showed mercy to the Gentiles, because Israel is disobedient, Israel may now be shown mercy in the same way God had mercy for the Gentiles. That is authoritative NT apostolic teaching right there. And it only makes sense if you consider the program God set forth.
Salvation comes from the Jews, for Jesus came to the lost nation of Israel. (Jesus said so Himself.) However, Israel rejected Jesus, and so the gospel went out to the Gentiles. After the fullness of the Gentiles comes in, God will finish with Israel. So by the rejection of Israel, all are saved. If God did that, there has to be a reason, which goes back to Israel being the chosen people of God through whom God sent the Messiah. As such, Jesus was only for the Jews, for God had promised Abraham, Isaac, Jacob, etc. Ultimately He promised David that the Messiah would sit on David's throne over... Israel. The church was a mystery in the Old Testament, revealed following the rejection of the Messiah by Israel, when the gospel moved to the Gentiles, and God's full plan was revealed in all of its glory.
You should use a passage that actually supports what you say. "That is nowhere presented in authoritative NT apostolic teaching, in fact, it is contrary to the NT apostolic teaching of the one olive tree of God's people, the church, of both OT and NT believers, going all the way back to Abraham, from whom unbelieving Israel has been cut off, and whose destiny is to be grafted back into that one olive tree, the NT church, IF (not "when") they do not continue in unbelief (Ro 11:16-23).
And that one body of believers, the one olive tree of God's people, the church, goes all the way back to Abraham (Ro 11:16-23).
16 And if the first piece of dough is holy, the lump is also; and if the root is holy, the branches are too.
17 But if some of the branches were broken off, and you, being a wild olive, were grafted in among them and became a partaker with them of the [f]rich root of the olive tree, 18 do not boast against the branches. But if you do boast against them, remember that it is not you who supports the root, but the root supports you. 19 You will say then, “Branches were broken off so that I might be grafted in.” 20 Quite right! They were broken off for their unbelief, but you stand by your faith. Do not be haughty, but fear, 21 for if God did not spare the natural branches, He will not spare you, either. 22 Behold then the kindness and severity of God; to those who fell, severity, but to you, God’s kindness, if you continue in His kindness; otherwise you also will be cut off. 23 And they also, if they do not continue in their unbelief, will be grafted in, for God is able to graft them in again. 24 For if you were cut off from what is by nature a wild olive tree, and were grafted contrary to nature into a cultivated olive tree, how much more will these who are the natural branches be grafted into their own olive tree?"
Nowhere does it say that the church goes all the way back to Abraham here. It is not there. It is again, your personal interpretation.
The meaning of remnant as defined by God with Elijah is...The word remnant is not exclusive to the Bible. It has a specific meaning in the Bible, but the word is not exclusive to the Bible.