And I will give them one heart, and put a new spirit within them. And I will take the heart of stone out of their flesh and give them a heart of flesh that they may walk in My statutes and keep My ordinances and do them. Then they will be My people, and I shall be their God. Ezekiel 11:19-20
While not talking about Christians or salvation, he who is doing this for his people (Israel) is the same God who saved us. This is essentially a picture of our salvation, which involves a heart transplant and a new spirit. With these in place, we are capable of obedience. As defiant as we might have been, we set out to keep his unburdensome commandments and do his will. Since he is the change agent in this transaction, this miracle can and will occur.
For this is the love of God, that we keep His commandments; and His commandments are not burdensome. 1 John 5:3