Hence the Reformation was indeed a catholic movement. If we keep in mind how variegated medieval catholicism was, the legitimacy of the reformers' claim to catholicity becomes clear. With men like Augustine and Bernard on their side, the reformers could well protest against the usurpation of the name "catholic church" by their opponents. A leading irenic and orthodox theologian of the seventeehth century, Johann Gerhard (4. 1637) spoke for all the reformers when he said:
If the papists want to prove the truth of the name "catholic" as applied to their church, let them demonstrate that the dogmas of their church are catholic, that is, that they are in conformity with the catholic writings of the prophets and apostles!...
If the papists want to deny us the name "catholic", let them demonstrate that we have seceded from the catholic faith and that we deny the mystery of the Trinity.
Not a new "Protestant" gospel, then, but the gospel of the true church, the catholic church of all generations, is what the Reformation claimed to be espousing. Substantiation for this understanding of the gospel came principally from the Scriptures; but whenever they could, the reformers also quoted the fathers of the catholic church. There were more to quote than their Roman opponents found comfortable. Every major tenet of the Reformation had considerable support in the catholic tradition.
There is more to quote of Pelikan too but space and time does not permit in this instance, yet inspite of Pelikan's move to Eastern Orthodoxy in his later years, I have no knowldege that he has retracted this positive evaluation of the Reformers. Let me know if you do.
According to Pelikan and to the Reformers
...for the church is truly catholic and apostolic when it relied upon biblical teaching, and it became sectarian when it admitted human opinions into the body of its teaching.
In light hearted conversations, I have heard of orthodox Protestant theologians/pastors quip - "we are the ones that are catholic, it is they that added the Pope". For Pelikan, this seems to be true.
But more to the point, what makes someone, a something? Is it the sign on the bill board? When speaking about human beings, the Christians were identified by their confession, hence, the Creed, or what they truly believe in. Back home there is a home grown religious group, and the group's name when translated in English is "The Church of Christ". In their apologetics, they would often ask hearers (and to reinforce the faith of their members) - "who is the real church of Christ? Well, no other than us, can you not see that that is our name, we are called by that name and because we are called by that name, we are what we are called?"
Begs the question, doesn't it? Actually there is a false premise, "we are called by that name" is not true, for in actuality it is "we call ourselves by that name".
You can apply this same type of analysis to the most obvious case in Christendom.