Gehazi became a leper because of his greed. In the story from 2 Kings, Gehazi was the servant of Elisha, a prophet of God. Naaman, a Syrian commander, was cured of leprosy by Elisha, and Naaman offered gifts to Elisha as a thank you. However, Elisha refused to accept any gifts. Gehazi, on the other hand, secretly followed Naaman and lied to him, asking for some of the gifts. Naaman gave him twice as much as he asked for, but when Gehazi returned, Elisha knew of his deceit and greed. As a result, Elisha cursed Gehazi with Naaman's leprosy, and Gehazi became a leper for the rest of his life.