Moses provided the Israelites with bread that came from heaven and in this passage, Jesus explains that God is now providing them with the Bread of Life through Jesus himself. We have an option in this life to try to fill ourselves with temporary things or be fulfilled by a relationship with God through Jesus' death. Peter believed and experienced the fulfillment of a personal relationship with God through Jesus; so much so that he saw no alternative to the life of service he was living alongside Jesus.