Psalm 99 poses a very difficult problem for modern readers. See if you can spot it:
The LORD reigns;
Let the peoples tremble!
He dwells between the cherubim;
Let the earth be moved!
The LORD is great in Zion,
And He is high above all the peoples.
Let them praise Your great and awesome name
He is holy.The King’s strength also loves justice;
You have established equity;
You have executed justice and righteousness in Jacob.
Exalt the LORD our God,
And worship at His footstool
He is holy.Moses and Aaron were among His priests,
And Samuel was among those who called upon His name;
They called upon the LORD, and He answered them.
He spoke to them in the cloudy pillar;
They kept His testimonies and the ordinance He gave them.
You answered them, O LORD our God;
You were to them God-Who-Forgives,
Though You took vengeance on their deeds.
Exalt the LORD our God,
And worship at His holy hill;
For the LORD our God is holy.
The problem for us comes in the portion in green. If we know our history, we’re on the alert immediately. We want to say, “Wait a minute, God! Moses did not keep Your testimonies and ordinance; he struck the rock. Aaron didn’t either; he made the golden calf. Samuel raised evil sons. How can You say such a thing about them?”
If we’re not familiar with the history, we still have trouble with the passage, because in the same breath, the Psalmist says that God forgave them, although He took vengeance on their evil deeds. So if there were offenses to forgive, if they were in fact guilty of evil deeds, then they clearly did not keep God’s testimonies and ordinance — right?
Wrong. Obviously wrong, because the Psalmist and the Holy Spirit say otherwise. But we cannot find it in our hearts to speak of Moses, Aaron, and Samuel in the way that the psalm speaks of them. We believe, right down to our bones, that it is an inaccurate, self-contradictory description.
In other words, we do not have the mind of Christ on this subject; we don’t see it as God does, and can’t speak of it as He does.
And yet, this is a psalm. We are supposed to sing it, just like the other psalms. Here, then, is the riddle: How can we sing it in good conscience, with understanding? How can the Psalmist and the Holy Spirit say, in the same breath, that Moses, Aaron, and Samuel kept God’s testimonies and His ordinance, and that He forgave them and avenged their evil deeds? How is that possible?
When we can answer that, we will know a little more about God’s forgiveness than we presently do.
And maybe we’ll become better at forgiving each other, too.
Full Contact Christianity 
Hey bro. Tim,
I just found this neat post. i have some thoughts, but I won’t go into all of them here. I’m surprised no one else has posted. But one thang I will say is that it seems the psalmist writing under divine inspiration is seeing it as God does, through the sacrifice of Christ for them, as He sees us, thankfully! God, being eternal, can see their sins as under the Blood, so to speak, before He even comes. So, though they, like we, are forgiven through Christ, yet our deeds often call for our Father’s loving chastening. Not sure this is the answer, but it’s how I see it. Glad to be corrected if I’m off. I enjoy & appreciate you & your blog bro. Tim. God Bless.