21 Do not turn away after useless idols. They can do you no good, nor can they rescue you, because they are useless.

Read 1 Samuel 12:21 Using Other Translations

And turn ye not aside: for then should ye go after vain things, which cannot profit nor deliver; for they are vain.
And do not turn aside after empty things that cannot profit or deliver, for they are empty.
Don’t go back to worshiping worthless idols that cannot help or rescue you—they are totally useless!