Matthew 16:18-19 is a key passage in the Bible for Catholics. In this passage, Jesus tells Peter that he is the rock on which he will build his church. This passage is significant because it establishes Peter as the first pope and the head of the Catholic Church. It also emphasizes the importance of the papacy in the Catholic faith. The passage begins with Jesus asking his disciples who the people say he is. The disciples respond with a variety of answers, but Peter says, "You are the Christ, the Son of the living God." Jesus is pleased with Peter's answer and says, "Blessed are you, Simon Bar-Jona, because flesh and blood has not revealed this to you, but my Father in heaven." Then Jesus says, "And I tell you, you are Peter, and on this rock I will build my church, and the gates of hell shall not prevail against it." The word "rock" in this passage can be translated in two ways: as "petros," which refers to a small stone, or as ...