How could it have changed since this prophecy has not yet been fulfilled?:
"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: Not according to the covenant that I made with their fathers in the day that I took them by the hand to bring them out of the land of Egypt; which my covenant they brake, although I was an husband unto them, saith the LORD: But this shall be the covenant that I will make with the house of Israel; After those days, saith the LORD, I will put my law in their inward parts, and write it in their hearts; and will be their God, and they shall be my people. And they shall teach no more every man his neighbour, and every man his brother, saying, Know the LORD: for they shall all know me, from the least of them unto the greatest of them, saith the LORD: for I will forgive their iniquity, and I will remember their sin no more" (Jer.31:31-34).
In this passage we can see that the "fathers" of both the house of Israel and the house of Judah are the physical descendants of Abraham, Isaac and Jacob. Their "fathers" broke the LORD's covenant and it was the physical descendants of Jacob who did that.
So these verses prove that sometime in the FUTURE all of the physical descendants of Abraham, Isaac and Jacob will be saved. For some reason you refuse to believe what is here revealed about what will happen in the future. Instead of accepting what is so clear about what this passage is saying you set out to prove that this prophecy cannot be trusted. Do you really think that the LORD was wrong when He foretold of these things happening?
That is true "now." But as Jeremiah 31:31-34 reveals, in the future the people belonging to both the house of Israel and the hose of Judah will be the physical descendants of Abraham, Isaac and Jacob.
"Therefore I tell you that the kingdom of God will be taken away from you and given to a people who will produce its fruit" (Mt.21:43; NIV).
In the following verse we can see exactly to which people the leadership of the kingdom will be given. The Lord said this to His Apostles:
"And I appoint unto you a kingdom, as my Father hath appointed unto me; That ye may eat and drink at my table in my kingdom, and sit on thrones judging the twelve tribes of Israel" (Lk.22:29-30).
Now that I have answered your point about the meaning of Matthew 21:43 then please address what I said about Jeremiah 31:31-34 and tell me why I am wrong when I say that those verses are speaking about the physical descendants of Abraham, Isaac and Jacob.
Thanks!