Summary: The Law was a good thing, it had its place in God's plans, but no one (except Christ) could observe it in its entirety. We are no longer under the Law, thank God that He did the new thing that He promised to Isaiah and Jeremiah, and which was accomplished
Isaiah 43: 16-19
God promises to do a new thing
Each and every book in the Old Testament records time and time again
how God’s chosen people just could not keep God’s Law;
for the same reason that any and every other tribe on the face of the earth could not,
because as it says in Jeremiah 17:9:
‘the (human) heart (that we all inherit from Adam and Eve)
is deceitful above all things, and beyond cure
(or at least human cure).
Many of us will remember South African Doctor Christian Barnard
and the announcement that he had performed the first heart transplant.
The man who received the donor heart was very happy
and lived a few more years than he would have done without it,
but he eventually died,
and even though I don’t know anything about him,
I am sure that no matter how well the heart’s donor lived
and how morally upstanding the recipient lived,
neither of them would be morally perfect or live sin-free lives.
God gave the Law to help people to know and understand His moral purity
and to know how to live lives pleasing to Him
but as Almighty God is omnipotent
He obviously knew that no human being, apart from His Son through Mary
would ever be able to keep it in its entirety.
So God’s ‘old thing’ in this context was the Mosaic Law,
the Ten Commandments and all the rules on animal sacrifices,
priestly rituals and festivals, hundreds of do’s and don’t’s.
The new covenant that God announced to Isaiah
would be new in extent or coverage
in that it went beyond Israel and Judah to include all the Gentile nations,
even thank God, us gathered here today.
The new covenant would be new in application
because it would be, or should be, written on our hearts and minds,
not only on tablets of stone or on doorposts,
and the new covenant would offer a new way to forgiveness,
not through animal sacrifices and ritual actions,
what we call ‘works’, but through grace and faith,
belief, that the sacrifice of Jesus on the cross,
the Agnus Dei, the spotless Lamb of God, pure and holy,
was enough to placate God’s wrath about our sin.
My ESV Study Bible contains a note to the effect that: (quote)
‘The new covenant stands in contrast to the old covenant,
in that the new cannot be broken as the old one was.’
‘The guarantee that it will not be broken is the grace mediated by Christ through His death and resurrection.’
‘The new covenant is all Gospel, gift,
whereas ‘the nature of the covenant which God made with Israel
was Law and works,
although obviously saving faith in Yahweh WAS required by the Jews
who hoped to benefit from it.’
‘Under the old covenant, the Law of God was engraved on tablets of stone
and placed in the Most Holy Place,
whereas under the new covenant
God writes His Law on the hearts of His people,
making us living Temples, made of living stones.’
‘The old covenant Law of Moses required obedience from the heart
and mediated forgiveness and hope through sacrifices
such as grain offerings, and the blood of animals such as doves and bulls.’