The Catholic Church is old, worldwide, and has a rich heritage. Yet, we have the Protestant movement. What is it about Catholicism that prompted this reforming effort?  Is prayer to Mary biblical?  What about penance and purgatory?  Are these things Catholic additions or biblical truths?

Introduction
Why is it Necessary to Write about Roman Catholicism?
Roman Catholicism, the Bible, and Tradition

Issues and Answers
Sola Scriptura: Is the Bible alone Sufficient?
Roman Catholic Terminology
Mary
Did Mary have other children?
Purgatory
Does Purgatory Deny the Sufficiency of Jesus' Sacrifice?
Purgatory and 1 Cor. 3:15
Council of Trent. Canons on Justification
The Roman Catholic view on justification
Comparison Grid between Catholicism and LDS and JW's
Is the Catholic Catechism's view on the Muslim god wrong?

Timeline of Heresy in the Roman Catholic Church