John Calvin on the Holy Spirit and Scripture

"It is easy to understand that we must give diligent heed both to the reading and hearing of Scripture, if we would obtain any benefit from the Spirit of God (just as Peter praises those who attentively study the doctrine of the prophets [2 Pet 1:19], though it might have been thought to be superseded after the gospel light arose), and, on the contrary, that any spirit which passes by the wisdom of God's word, and suggests any other doctrine, is deservedly suspected of vanity and falsehood.  Since Satan transforms himself into an angel of light, what authority can the Spirit have with us if he be not ascertained by an infallible mark?  And assuredly he is pointed out to us by the Lord with sufficient clearness; but these miserable men err as if bent on their own destruction, while they seek the Spirit from themselves rather than from him.  But they say that it is insulting to subject the Spirit, to whom all things are to be subject, to the Scripture; as if it were disgraceful to the Holy Spirit to maintain a perfect resemblance throughout, and be in all respects without variation consistent with himself.  True, if he were subjected to a human, an angelical, or to any foreign standard, it might be thought that he was rendered subordinate, or, if you will, brought into bondage, but so long as he is compared with himself, and considered in himself, how can it be said that he is thereby injured?  I admit that he is brought to a test, but the very test by which it has pleased him that his majesty should be confirmed.  It ought to be enough for us when once we hear his voice; but lest Satan should insinuate himself under his name, he wishes us to recognize him by the image which he has stamped on the Scriptures. The author of the Scriptures cannot vary, and change his likeness.  Such as he there appeared at first, such he will perpetually remain.  There is nothing [humiliating] to him in this, unless we are to think it would be honorable to for him to degenerate, and revolt against himself" (Institutes of Christian Religion, John Calvin).