We looked at where we find the 13 Attributes of Divine Mercy last week, Exodus 34.6-7: The Lord passed before him and proclaimed, “The Lord, the Lord, a God merciful and gracious, slow to anger, and abounding in steadfast love and faithfulness,keeping steadfast love for thousands, forgiving iniquity and transgression and sin, but who will by no means clear the guilty, visiting the iniquity of the fathers on the children and the children's children, to the third and the fourth generation.” That revelation was given to a nation who had just committed terrible sin against the God who had brought them out of the land of Egypt, out of the house of slavery. A sinful nation needed a merciful God if they were to co-exist and fulfill their destiny of being a kingdom of priests and living in the Promised Land.
The Jewish sages see this as a second covenant if you will rather than a renewal of the first covenant when the 10 Commandments were given at Mt Sinai in Exodus 20. There is a difference between the two because of the new revelation of God as not only great and good to His people but merciful above all else. He isn't just a jealous God who punishes, that isn't even His primary characteristic, but until they understand who they are, a stiff necked people prone to sin, they can't understand why it is vitally important that He is, above all, merciful. That God can even dwell in the midst of a stiff necked nation and in Him all His promises are fulfilled for those who love Him and confess their sin. That's the Good News Jesus came to bring not to a nation only but to all mankind.
That is the reason all heaven sings a new song when Jesus appears before the throne, as a lamb standing, as though it had been slain in Revelation 5. Whereas before the nation of Israel was a kingdom and priests, listen to the new song:
“Worthy are you to take the scroll
and to open its seals,
for you were slain, and by your blood you ransomed people for God
from every tribe and language and people and nation,
and you have made them a kingdom and priests to our God,
and they shall reign on the earth.”