God found fault with his people.
They did not fulfill their obligations in the Old Covenant.
This is why a New Covenant was necessary.
As Paul wrote no one would be declared righteous through obedience to the law. It can't be done.
So God sent Jesus.
And He fulfilled the righteous requirements of the law.
But even better, He ushered in the New Covenant.
And this new one is not like the old. It's better in every way. Because it's based on God's promises and faithfulness.
Which means he will deliver on all his promises to you.
As the writers of Hebrews wrote, Jesus is the guarantor of this better covenant. And you can count on Him.
And that's good news!