*It is not we who call ourselves Lutherans. Rather, our adversaries call us that. We allow this to the extent that this title is an indication of the consensus that our churches have with the orthodox and catholic doctrine that Luther set forth from Holy Writ. Therefore we allow ourselves to be named after Luther, not as the inventor of a new faith but as the asserter of the old faith and the cleanser of the church from the stains of Papist dogmas. Consequently, we also do not reject the names “Christian” and “catholic,” nor do we render ourselves unworthy of them by the approval of any heretical dogma, as did the Arians, Nestorians, Eutychians, etc. Rather, we are called “Christians” from Christ as the only Author and Teacher of our faith. We are called “catholics” from our consensus with the catholic faith. We are called “Lutherans” from Luther as the asserter and defender of that faith, but especially as the reformer whom God raised up (*Johann Gerhard, On the Church, Theological Commonplace XXV, § 156; Latin: vol. 5, p. 394).
We have not separated from the church catholic. The Donatists said that the church had perished from the entire earth. We say, on the contrary, that the church has always continued and will endure forever. Consequently, we not only acknowledge that the church has been preserved under the papacy in earlier times, we also profess that the church is still being gathered to God by a loud voice in the middle of Rome. The Donatists enclosed the church within the borders of Africa alone... But we believe and confess that the church is catholic and universal. The Papists should see if they can free themselves completely from the error of the Donatists because they say that all catholics have disappeared from the world except those alone who have remained in the party of the bishop of Rome. -- Blessed Johann Gerhard, *The Church* p. 184.
We have departed neither from the catholic faith nor the church catholic; rather, we have retained the catholic faith and have renounced the errors, idol-madness, and superstitions that have been brought into the church. In fact, instead of having departed from the faith of the catholic church, much rather we have not even departed from the faith of the Roman church to the extent that it agrees with the old catholic and apostolic faith. We admit that we have departed from not a few articles of the modern Roman faith. But this is not a defection from the old catholic faith, but rather a return to the original catholic faith that has been deformed in many ways in the Roman church with new inventions, superstitions, and additions, and is a turning back to Christ as the only teacher of the faith. -- Blessed Johann Gerhard, On the Church, p. 344.
Meum enim propositum est...antiquos legere, singula probare, quae bona sunt retinere, et de fide Ecclesiae Catholicae non recedere (Matthäus Ludecus, Vesperale, 1589).
Polycarp Leyser: “Lutherans have far more in common with Romanists than with Calvinists.” quoted in Nischan, Becoming Protestants, 105.