Calvin on the New Birth

But the Scripture positively affirms, that to circumcise the hearts of men, is the work of God alone: nor is regeneration ascribed to any other than God Himself.  -- John Calvin

That obstinacy and enmity are common to all men, I fully admit; and I also maintain, that the heart of no man is softened, and made flexible and obedient to the will of God, until God gives him the will and power to do what He commands. For why are we called "new creatures?" but because "we are His workmanship; created unto good works?" --But, I pray you, what kind of a division, and how iniquitous a division, of all praise and glory, would it be, to make God the Creator of us mortal men; and yet to make each one of us his own creator unto righteousness and eternal life! In this way, God would only have for Himself the praise of ineffectual and failing grace. That portion of the glory which is the far more excellent, would fall to our lot. But the Scripture positively affirms, that to circumcise the hearts of men, is the work of God alone: nor is regeneration ascribed to any other than God Himself. Hence it is, that whatever in man is created anew, in the image of God, is called "spirit." "That which is born of the flesh is flesh; and that which is born of the Spirit, is spirit." (John 3: 6.) God does, indeed, frequently invite us to repentance: but He Himself is everywhere declared to be the author of conversion: His "law" is said "to convert souls."

Calvin, John (2011-11-24). Calvin's Calvinism: A Treatise on the Eternal Predestination of God. Translated by Henry Cole. (Kindle Locations 1596-1610). . Kindle Edition.