The subject of Psa. 136 is the charging of the people to give thanks to Jehovah for His everlasting lovingkindness.
New book
Speaking the Truth in Love
This is how denominations are formed. The main direction is to come out of the system; it cannot change. "I began to realize that our practices have differed and deviated from our vision. Our vision was the same, our teaching was mostly the same, the truth is always the same, but our practice has really differed."