Reading the Psalms

This summer I successfully committed myself to reading the New Testament for the first time, starting with Matthew and continuing through Revelations at about four chapters daily.  My Gideon shirt pocket version follows with Psalms, so I proceeded onward to Psalm 1, finding a Messianic tone that I expected to be an adulteration of the classic Hebrew text.  I diverted to Sefaria's electronic version, pacing about five per session with one or two sessions daily.  I'm past 100, about 2/3 done, recognizing those that appear in our daily or shabbos liturgy though with a more pedestrian and probably literal translation than the editors of the Siddur assembled to sound more erudite or spiritual.

Those of the liturgy are selected for the occasion from the pool of 150.  Reading in sequence leaves a very different impression.  The poems are attributed to King David who repeatedly described himself as unfairly persecuted by evil men out to get him.  Only his Lord could extricate him from these recurrent travails, usually did, and got a few words of thanks for coming through in the clutch.  While monotheism was a core tenet, the poems read differently, not that there is only one God but that my One God is better than anyone else's, be they one God or part of a polytheistic team.  

He tended to see the world around him in black & white, you were either good and a follower of God, or you were evil and out to get him, with perhaps the exception of the references to Saul who also followed the same God but was still out to get him.  

One hundred psalms into the series, I do not have a sense of how the sequence was determined.  It's probably not random, as the earlier ones seemed more consistently persecutorial than the middle ones.  I still have the final third to read and think about, so maybe the answer will become more apparent.