It cannot be too strongly emphasized at the outset that Calvin did not think of himself as “Reformed” in the sense of inner-Protestant polemics. Calvin was not a Calvinist but an Evangelical, and what he thought about Luther can only be understood from this viewpoint. He identified himself wholly with the common Protestant cause and never faced the Wittenbergers as the sponsor of a rival movement. This was at no time made more plain than when Calvin learned of the struggle between the Saxon Lutherans and Heinz von Wolfenbüttel (1545). He immediately obtained permission from the Genevan authorities to hold a special service of intercession, and from his pulpit he exhorted the people of Geneva: “I am not speaking of Geneva alone, but of all towns and territories where the gospel is proclaimed.… May we set ourselves apart? May we say, ‘They are far away from us’? No, they belong to the church, and we are their members.” Moreover, as is well known, Calvin testified to his solidarity with the Lutherans by accepting the Augsburg Confession.14 Of course, the eucharistic debates repeatedly menaced the relations between Calvin and the Lutherans. But it is common knowledge that on the points at issue between Luther and Zwingli he recognized the validity of Luther’s case. And he did not permit even the bitterness of his debate with Joachim Westphal to shake his confidence in the German Reformer, whose memory he continued to cherish.
—B. A. Gerrish, The Old Protestantism and the New: Essays on the Reformation Heritage (London; New York: T&T Clark, 2004), 29.