Here, then, we have the principle tinctured with the blood of our Puritan, Covenanter and Huguenot forefathers — that which is not commanded, either explicitly or implicitly in the Scriptures, is prohibited to the church. She can utter no new doctrine, make no new laws, ordain no new forms of government, and invent no new modes of worship. This is but a statement of a fundamental principle of Protestantism, contra-distinguishing it from Rationalism on the one hand and Romanism on the other — that the Scriptures, as the word of Christ, are the complete and ultimate rule of faith and duty. They are complete, since they furnish as perfect a provision for the spiritual, as does nature for the physical, wants of man, and therefore, exclude every other rule as unnecessary and superfluous. They are ultimate because, being the word of God, they must pronounce infallibly and supremely upon all questions relating to religious faith and practice. The duty of the church, consequently, to conform herself strictly to the divine word, and her guilt and danger in departing from it would seem to be transparently evident. But the clearest principles, through the blindness, fallibility, and perverseness of the human mind, frequently prove inoperative in actual experience; and the history of the church furnishes lamentable proof that the great, regulative truth of the completeness and supremacy of the Scriptures constitutes no exception to this remark.

John L. Girardeau (1825–98) “The Discretionary Power of the Church” (HT: ChortlesWeakly)