The biggest challenge for Protestants when discussing Catholic doctrine is not whether asking for the saints’ intercession is right, or whether transubstantiation is true, or whether Mary was really immaculately conceived, and so on. Those are important teachings in their own right and worthy of discussion; however, far surpassing them in importance is the question of authority, because the authority one chooses to follow and obey is really the primary driving force behind what one believes.

Therefore, before discussing issues like transubstantiation, the Immaculate Conception, asking saints for their intercession, Purgatory, and other doctrines, the issue of authority must be honestly confronted.

For Protestants, the only infallible authority is the Bible. That view of authority is known as sola scriptura (scripture alone). However, sola scriptura is a self-refuting doctrine, since one cannot prove the doctrine of Scripture alone using Scripture alone. This should be a huge, gargantuan red flag for Protestants: Just exactly what, then, is their authority?

This is a crucial question that all Protestants should face boldly and answer honestly.