consider the olive tree

I am talking to you Gentiles. Inasmuch as I am the apostle to the Gentiles, I make much of my ministry in the hope that I may somehow arouse my own people to envy and save some of them. For if their rejection is the reconciliation of the world, what will their acceptance be but life from the dead? If the part of the dough offered as firstfruits is holy, then the whole batch is holy; if the root is holy, so are the branches.
If some of the branches have been broken off, and you, though a wild olive shoot, have been grafted in among the others and now share in the nourishing sap from the olive root, do not boast over those branches. If you do, consider this: You do not support the root, but the root supports you. You will say then, "Branches were broken off so that I could be grafted in." Granted. But they were broken off because of unbelief, and you stand by faith. Do not be arrogant, but be afraid. For if God did not spare the natural branches, he will not spare you either.
Consider therefore the kindness and sternness of God: sternness to those who fell, but kindness to you, provided that you continue in his kindness. Otherwise, you also will be cut off. And if they do not persist in unbelief, they will be grafted in, for God is able to graft them in again. After all, if you were cut out of an olive tree that is wild by nature, and contrary to nature were grafted into a cultivated olive tree, how much more readily will these, the natural branches, be grafted into their own olive tree!