The book of Proverbs has a few wise verses on believers befriending non-believers: "The righteous should choose his friends carefully, for the way of the wicked leads them astray" (Proverbs 12:26). We should stay away from foolish people (Proverbs 13:20, 14:7), from people who lose their temper easily (Proverbs 22:24), and from the rebellious (Proverbs 24:21). All these things represent those who have not been saved.