R.C. Sproul put it this way in his wonderful book, Faith Alone: An Evangelical Doctrine of Justification by Faith:
"Does saving faith require a trust in the righteousness of Christ alone as the grounds of our justification? Or may a person have a different view of the gospel and still be a Christian?"
"The Reformation was waged, not over the issue of justification by faith, but over the issue of justification by faith alone. It was the Sola of Sola Fide that was the central point of dispute."
Luther's Great Hymn: A Mighty Fortress is Our God
