Psalm 106, the final psalm in Book IV of the Psalter, is the flip side of the coin of Psalm 105.
Whereas Psalm 105 showed God’s faithfulness in all his doings with his people in history. Psalm 106 is a confession of all the failings of God’s people in response.
The person praying Psalm 106 takes all these sins for his own, which means the person praying this psalm is none other than Jesus Christ.
He has taken the sins of all his people upon himself.
This is why the psalm ends with a word of blessing and salvation. For when God’s faithfulness is matched with our unfaithfulness, The Lord triumphs over them.
A feature of this psalm is to also not take God’s grace in vain. We are not called to embrace sin because God forgives, but are warned to not be like the people this psalm details. Paul does this as well in 1 Corinthians 10.