What does Deuteronomy 27:26 mean?

Anyone who ignores what God has said in his law and doesn't actually live by it is under a curse. You can't just hear these words—you have to do them. Deuteronomy 27:26 - Modern Text Bible

(This verse sums up the previous curses, stressing that it's not enough to know God's instructions; you have to follow them to avoid bringing trouble on yourself.)