A new heart also will I give you, and a new spirit will I put within you: and I will take away the stony heart out of your flesh, and I will give you an heart of flesh. A new heart also will I give you - I will change the whole of your infected nature; and give you new appetites, new passions; or, at least, the old ones purified and refined. The heart is generally understood to mean all the affections and passions.
And a new spirit will I put within you - I will renew your minds, also enlighten your understanding, correct your judgment, and refine your will, so that you shall have a new spirit to actuate your new heart.
I will take away the stony heart - That heart that is hard, impenetrable, and cold; the affections and passions that are unyielding, frozen to good, unaffected by heavenly things; that are slow to credit the words of God. I will entirely remove this heart: it is the opposite to that which I have promised you; and you cannot have the new heart and the old heart at the same time.
And I will give you a heart of flesh - One that can feel, and that can enjoy; that can feel love to God and to all men, and be a proper habitation for the living God.