This is a restrained song of praise that has two extra verses for weddings. The text based on Psalms 135 and 136 is by Mike Balhoff. The music is by Darryl Ducote and Gary Daigle. The were all members of The Dameans.
OCP will sell you the sheet music and provide the text in their preview. GIA have a choral arrangement that takes the key from C to Eb if you are in performance mode.
I enjoyed making this backing: