The Psalms do professional theologians no favors. None of God's attributes are known apart from his actions in history, there are no timless truths in the Psalms. I just noticed this today even though a few theologians have been saying things like it for years now.
The Lord is to be thanked because he did something, for his steadfast love endures for ever.
That is typically the pattern.
Also the Psalms are written be people in whose consiousness is burned the fact that YHWH delivered them from Egypt. Once again God is known for his actions in history: his self disclosure and his saving power. Even the psalms about the law and God's statues are about the law given to the people saved from Egypt.
This makes me think that as Christians our identity should still be connected to the God who delivered from Egypt, but more importantly, burned into our own conciousness should be God's actions on our behalf in history, his self disclosure and saving power in the person and work of Jesus Christ. So perhaps in the same way that the first 19 chapters of Exodus were apparently always on the minds of the Psalmists so to as Christians ought the four gospels always be on our minds.