The "O": Used before a name in direct address especially in solemn or poetic language, to lend earnestness to an appeal. An expression of surprise, pain, annoyance, longing, gladness, etc. (Webster's Dictionary)
Look at almost any Psalm & you will see the phrase "O LORD" or something very much like it. When we pray, how many of us address God by saying "O God" or "O LORD", "O Most High" (or "O" Anything)?! More often than not these days, we drop the "O" for the comfort of familiarity. Our culture no longer necessitates the use of archaic formalities as it concerns faith. We are sons & daughters of God our Father. "O God" has become just "God". He is the average Joe, the everyday Bob, the helpful Dave. He's Dad, He's Pop. He's our Faithful Friend. But there's a danger in deleting the "O" from our prayer vocabulary. What's to separate God Most High from anyone else in our life? Where is the awe, the reverence for such a One like Him?
We no longer speak like the Psalmists. In order to be relevant in today's world, we need to keep up with the times. Or do we? What would happen if we began addressing God with a simple "O" or other accent of honour? Would it begin to change us? Would it make us mindful of the incomprehensible reality of Who He is? Would it perhaps help us to remember that though we are His dearly loved children, we are also made of dust & dependent on Him for our very lives?
Hear my prayer, O LORD! Listen to my cries for help! Don't ignore my tears. For I am Your guest- a traveler passing through, as my ancestors were before me. Psalm 39:12 NLT