In dialoging with Roman Catholics on sola fide, I have sometimes argued from their point of view: that is, the doctrine of justification was not, at the time of Luther’s writing, dogmatically defined in the Roman Catholic sense. In other words, Luther had freedom to hold the view on justification that he did within a Roman Catholic framework. I picked up a copy yesterday of Jaraslov Pelikan’s book, Obedient Rebels: Catholic Substance and Protestant Principle in Luther’s Reformation [New York: Harper and Row, 1964].
I found this quote on page 51-52 quite interesting:
“Existing side by side in pre-Reformation theology were several ways of interpreting the righteousness of God and the act of justification. They ranged from strongly moralistic views that seemed to equate justification with moral renewal to ultra-forensic views, which saw justification as a 'nude imputation' that seemed possible apart from Christ, by an arbitrary decree of God. Between these extremes were many combinations; and though certain views predominated in late nominalism, it is not possible even there to speak of a single doctrine of justification.”
I share this for one reason: don't get sucked into those silly arguments that "sola fide" was a theological "novum" previous to the Reformation. Pelikan says elsewhere:
"All the more tragic, therefore, was the Roman reaction on the front which was most important to the reformers, the message and teaching of the church. This had to be reformed according to the word of God; unless it was, no moral improvement would be able to alter the basic problem. Rome’s reactions were the doctrinal decrees of the Council of Trent and the Roman Catechism based upon those decrees. In these decrees, the Council of Trent selected and elevated to official status the notion of justification by faith plus works, which was only one of the doctrines of justification in the medieval theologians and ancient fathers. When the reformers attacked this notion in the name of the doctrine of justification by faith alone—a doctrine also attested to by some medieval theologians and ancient fathers—Rome reacted by canonizing one trend in preference to all the others. What had previously been permitted (justification by faith and works), now became required. What had previously been permitted also (justification by faith alone), now became forbidden. In condemning the Protestant Reformation, the Council of Trent condemned part of its own catholic tradition."
Source: Jaroslav Pelikan, The Riddle of Roman Catholicism (New York: Abingdon Press, 1959), pp. 51-52.
Simply use the above quotes, and then say "What does the Bible say about justification?" History doesn't determine doctrine. Councils don't determine doctrine. Only the Bible determines doctrine.