“Lutheranism has by this time become in most places almost simple heresy of infidelity; it has terminated, if it has even yet reached its limit, in a denial both of the Canon and the Creed, nay, of many principles of morals. Accordingly the question arises, whether these conclusions are in fairness to be connected with its original teaching or are a corruption. And it is no little aid towards its resolution to find that Luther himself at one time rejected the Apocalypse, called the Epistle of St. James ‘straminea,’ condemned the word ‘Trinity,’ fell into a kind of Euctychianism in his view of the Holy Eucharist, and in a particular case sanctioned bigamy. Calvinism, again, in various distinct countries, has become Socinianism, andCalvin himself seems to have denied our Lord’s Eternal Sonship and ridiculed the Nicene Creed.”
-John Henry Newman in An Essay On the Development of Doctrine.