Romans 11:20-22

New Century Version

²⁰ That is true. But those branches were broken off because they did not believe, and you continue to be part of the tree only because you believe. Do not be proud, but be afraid. ²¹ If God did not let the natural branches of that tree stay, then he will not let you stay if you don’t believe.

²² So you see that God is kind and also very strict. He punishes those who stop following him. But God is kind to you, if you continue following in his kindness. If you do not, you will be cut off from the tree.