Religious Question

I was reading The Actor and the Housewife by Shannon Hale (review) and came to a quote that sums up well something I've thought in the past.

"Why would calling on the Lord's name ever be in vain if he were really there to listen?"

Don't get me wrong, I do not and will not take the Lord's name in vain, but I have questioned this before.  Occasionally in the past I've said "Oh praise the Lord Jesus," but really am extremely grateful (for some reason that word is hard for me to spell) for the situation.  This is a real question.  Please let me know your thoughts. 

P.S. Cooking blog coming soon.