True, "pure doctrine," "unity in the pure doctrine of the Gospel," such was the shibboleth of the faithful Lutherans over against the Melanchthonians and other errorists. But this was neither reprehensible doctrinalism nor a corruption of original Lutheranism, but the very principle from which it was born and for which Luther contended throughout his life--a principle of life or death for the Lutheran Church. It was the _false_ doctrine of justification which made Luther a most miserable man. It was the _pure_ doctrine as taught by St. Paul which freed his conscience, transported him into Paradise, as he himself puts it, and made him the Reformer of the Church. Ever since, purity of doctrine was held, by Luther and all true Lutheran theologians, to be of paramount import to Christianity and the Church. Fully realizing that adulteration of any part of the Christian doctrine was bound to infect also the doctrine of faith and justification and thus endanger salvation, they earnestly warned against, and opposed, every deviation from the clear Word of God, no matter how insignificant it might appear. They loved the truth more than external peace, more even than their own lives. Hence they found it impossible to be silent, apathetic, and complacent spectators while the Philippists and others denied, attacked, and corrupted the truth taught by Luther from the Word of God. Accordingly, since the Leipzig Interim involved and maintained doctrines and principles subversive of genuine Lutheranism and was prepared, introduced, and defended by the very men who were regarded as pillars of the Lutheran Church, it was evident from the outset that this document must of necessity precipitate most serious internal troubles. From the moment the Wittenbergers cast the Interim as a firebrand into the Church, a domestic warfare was unavoidable,--if indeed any true disciples of Luther still remained in the Church of which he, and not Melanchthon, was the founder. While the Augsburg Interim resulted in an external theological warfare of the Lutherans against the Romanists, the Leipzig Interim added a most serious domestic conflict, which conscientious Lutherans could not evade, though it well-nigh brought our Church to the brink of destruction. For now the issue was not merely how to resist the Pope and the Romanists, but, how to purge our own Church from the Interimists and their pernicious principles. And as long as the advocates of the Interim or of other aberrations from the old Lutheran moorings refused to abandon their errors, and nevertheless insisted on remaining in the Church, there was no real unity in the truth. Hence there could also be no true peace and brotherly harmony among the Lutherans. And the way to settle these differences was not indifferently to ignore them, nor unionistically to compromise them by adopting ambiguous formulas, but patiently to discuss the doctrines at issue until an agreement in the truth was reached, which finally was done by