“No. The Church is Christ’s bride”
No, that is not correct. The Gentile church can be “cut off” if they doesn’t stand fast - just like Israel was...
“Now I am speaking to you Gentiles. Inasmuch then as I am an apostle to the Gentiles, I magnify my ministry in order somehow to make my fellow Jews jealous, and thus save some of them. For if their rejection means the reconciliation of the world, what will their acceptance mean but life from the dead? If the dough offered as firstfruits is holy, so is the whole lump, and if the root is holy, so are the branches. But if some of the branches were broken off, and you, although a wild olive shoot, were grafted in among the others and now share in the nourishing root of the olive tree, do not be arrogant toward the branches. If you are, remember it is not you who support the root, but the root that supports you. Then you will say, “Branches were broken off so that I might be grafted in.” That is true. They were broken off because of their unbelief, but you stand fast through faith. So do not become proud, but fear. For if God did not spare the natural branches, neither will he spare you. Note then the kindness and the severity of God: severity toward those who have fallen, but God’s kindness to you, provided you continue in his kindness. Otherwise you too will be cut off.”
-Rom 11
“Otherwise you too will be cut off.”
Upon this rock...the gates of hell shall not prevail, etc.
You wrote:
“No, that is not correct. The Gentile church can be “cut off” if they doesn’t stand fast - just like Israel was...”
This is not the “Gentile church”. It is simply the Church. There are no gentiles or Jews in the Church - there are only Christians. And the Church cannot be cut off from God because it is from Christ.