Through careful theologizing and precise explanations, Catholics and Protestants can find a way to agree that we are "saved by faith alone."
But that doesn't settle the matter. Select theologians agreeing on how it's possible to use the same words does not make the actual disagreement go away in real life.
Similarly, Christians and Muslims can rationalize that both worship the same God, but that doesn't translate into anything meaningful.
Whatever words might make us feel good, it still stands that obedience in the Christian life -- what we do -- is critical; and worshiping Jesus is critical.