Deuteronomy 13:6-8

If your very own brother, or your son or daughter, or the wife you love, or your closest friend secretly entices you, saying, “Let us go and worship other gods” (gods that neither you nor your fathers have known, gods of the peoples around you, whether near or far, from one end of the land to the other), do not yield to him or listen to him. Show him no pity. Do not spare him or shield him.