The context of that quote from Yeshua was in response to Kefa (Peter), who had just told Yeshua, “You are the Mashiach, Ben of the Elohim Chayim! The Master then exclaims “Flesh and Blood did not reveal this to you Kefa! But my Father in Heaven! You are the prototype! My first living stone..... And with such stones I will build my eidah!, my movement, my Chaverah! And the gates of Hell itself will fall by it, they will not be able to resist its power. This will happen in our days IF we can find Peter. Remember the scene in Robin Williams film “Hook”? The little lost boy holds his face and looks deep in his eyes until suddenly he says “Oh, there you are Peter!” He had forgotten that He himself was Peter Pan; thought he was a lawyer. He had to remember. And so for the sincere Christian. Go back and do the first works and return to your true Identity. For true believers that identity is Israel. There is no other Covenant Nation.
The Israel of God has both the natural branches and the wild branches that were grafted in. The Church has no covenant but gets in under those of the nation of Israel. Salvation is of the Jews.
That changed with the coming of Christ.