Romans 11:20-24

20Granted. But they were broken off because of unbelief, and you stand by faith. Do not be arrogant, but tremble.

21For if God did not spare the natural branches, he will not spare you either. 22Consider 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. 23And if they do not persist in unbelief, they will be grafted in, for God is able to graft them in again.

24After 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!