The Lord knows right well that you cannot change your own heart, and cannot cleanse your own nature; but He also knows that He can do both. He can cause the Ethiopian to change his skin, and the leopard his spots. Hear this, and be astonished: He can create you a second time; He can cause you to be born again. This is a miracle of grace, but the Holy Ghost will perform it.
It would be a very wonderful thing if one could stand at the foot of the Niagara Falls, and could speak a word which should make the river Niagara begin to run up stream, and leap up that great precipice over which it now rolls in stupendous force. Nothing but the power of God could achieve that marvel; but that would be more than a fit parallel to what would take place if the course of your nature were altogether reversed. All things are possible with God. He can reverse the direction of your desires and the current of your life, and instead of going downward from God, He can make your whole being tend upward toward God.
That is, in fact, what the Lord has promised to do for all who are in the covenant; and we know from Scripture that all believers are in the covenant. Let me read the words again: A new spirit will I put within you: and I will take away the stony heart out of your flesh, and will give a heart of flesh. (Ezekiel 11:19).