If the doctrine of the apostles and the prophets is the foundation of the church, the former must have had its certainty before the latter began to exist…
For if the Christian church was founded at first on the writings of the prophets, and the preaching of the apostles, that doctrine, wheresoever it may be found, was certainly ascertained and sanctioned antecedently to the church, since, but for this, the church herself never could have existed.
Nothing, therefore can be more absurd than the fiction, that the power of judging Scripture is in the church, and that on her nod its certainty depends…
As to the question, How shall we be persuaded that it came from God without recurring to a decree of the church?
It is just the same as if it were asked, How shall we learn to distinguish light from darkness, white from black, sweet from bitter?
Scripture bears upon the face of it as clear evidence of its truth, as white and black do of their color, sweet and bitter of their taste.
John Calvin, Institutes, I.7.3