After a description of the five solas of the Protestant Reformation and their biblical basis, the rejection of the solas by the Roman Catholic Church at Trent and Vatican I is traced, focusing on revelation, justification, and worship. The account of Roman Catholic theology is brought up to date by an examination of changes that occurred at Vatican II. A different stance toward Protestants and the wider world is explained by a shift in the Church’s view of the nature-grace relationship. Despite this change, the core commitments of the Catholic Church on revelation, justification, and worship remain unaltered. They are held within a less adversarial but still expansionist Rome-centered theology that Protestants must continue to resist.