John 1:17 For the law was given through Moses; grace and truth came through Jesus Christ.
Without the law being written down, we may well have forgotten what is good and bad over time; but God made sure it was written down in full.
Now, what we have through Jesus Christ is so much more than the law – we have a promise which is the embodiment of the law!
Jesus came to ensure we understand just how much He gave us through His grace – because we already had the law to show us how we fall short of God’s wishes!