If we give up and turn our backs on all we've learned, all we've been given, all the truth we now know, we repudiate Christ's sacrifice
and are left on our own to face the Judgment - and a mighty fierce judgment it will be!
If the penalty for breaking the law of Moses is physical death,
what do you think will happen if you turn on God's Son, spit on the sacrifice that made you whole, and insult this most gracious Spirit?
This is no light matter. God has warned us that he'll hold us to account and make us pay. He was quite explicit: "Vengeance is mine, and I won't overlook a thing," and, "God will judge his people."
Nobody's getting by with anything, believe me.