After Obi-Wan Kenobi is slain by Darth Vader, Luke is beside himself with grief, and feels completely unmoored by the loss of his mentor. He grieves the death, but slowly musters the courage to keep going, and even receives some encouragement from an ethereal disembodied voice—that of the now-deceased Obi-Wan. When Obi-Wan fights with Darth Vader before his death, he warns that if Vader strikes him down, he will only become more powerful. This proves to be true, when he continues to speak to Luke and motivate him even after death. It is this spiritual guidance that gives Luke hope and keeps him going.