Book excerpt: The Mass may seem routine, and it may be the common property of millions of Catholics, but much lies beneath. Mike Aquilina not only answers practical questions about this central act of Catholic worship, but also walks you through the Mass, explaining the meaning behind the prayers and practices. Find answer to such questions as: What is the Real Presence? What are the Jewish roots of the Mass? Why is the Mass a sacrifice? Why do some people receive Communion on the tongue and others in the hand? You may be surprised by how much you've missed in your understanding of the Mass.