Spirit & the Word - Calvin's Institutes 5

John Calvin: 

"But I answer, that the testimony of the Spirit is superior to reason.  For as God alone can properly bear witness to his own words, so these words will not obtain full credit in the hearts of men, until they are sealed by the inward testimony of the Spirit.  The same Spirit, therefore, who spoke by the mouth of the prophets, must penetrate our hearts, in order to convince us that they faithfully delievered the message with which they were divinely intrusted...the only true faith is that which the Spirit of God seals on our hearts."  Institutes of Christian Religion, Vol. I, 72-73.