Sound Doctrine versusFalse Doctrine

"'If there ever was a strictly conservative body, it surely is the Missouri Synod. Nevertheless, this growth!...It is a mark of the pastors and leaders of the Missouri Synod that they never, aye, never, tire of discussing doctrine on the basis of Scripture and the Confessions. That is one trait that may be called the spirit of Missouri. People who thus cling to doctrine and contend for its purity are of an entirely different nature from the superficial unionists who in the critical moment will declare five to be an even number. God will bless all who value His Word so highly.'"
Dr. Lenski, Kirchenzeitung, May 20, 1922)cited in W. A. Baepler, "Doctrine, True and False," The Abiding Word, ed., Theodore Laetsch, St. Louis: Concordia Publishing House, 1946, II, p. 515f.

"We should not consider the slightest error against the Word of God unimportant."
What Luther Says , An Anthology, 3 vols., ed., Ewald Plass, St. Louis: Concordia Publishing House, 1959, II, p. 637.

"Error and heresy must come into the world so that the elect may become approved and manifest. Their coming is in the best interests of Christians if they take the proper attitude toward it. St. Augustine, who certainly was sufficiently annoyed by wretched sectaries, says that when heresy and offense come, they produce much benefit in Christendom; for they cause Christians industriously to read Holy Scriptures and with diligence to pursue it and persevere in its study. Otherwise they might let it lie on the shelf, become very secure, and say: Why, God's Word and the text of Scripture are current and in our midst; it is not necessary for us to read Holy Scripture."
What Luther Says, An Anthology, 3 vols., ed., Ewald Plass, St. Louis: Concordia Publishing House, 1959, II, p. 639.

“You cannot of a truth be for true doctrine without being unalterably opposed to false doctrine. There can be no 'positive theology' where the God-given negatives have been eliminated from the Decalog."
Norman A. Madson, Preaching to Preachers, Mankato: Lutheran Synod Book Company, 1952. Preface.