The "law of Christ" in the New Covenant is the law of love — not the Mosaic Law written on the heart

When Jeremiah 31 says God will write his law on the heart, this does not necessarily mean the Law of Moses. It can refer to the law that Abraham was under, or it can refer to the law of Christ—love one another. The New Covenant's "law" is the law of love, not the full Mosaic Code reinstated internally. This is consistent with the Pauline concept of the "law of Christ" (Galatians 6:2).