ok let's just assume for the sake of argument God does
exist... even if you're an atheist pretend you're in a philosophy class and you're fleshing out the logic of various particular arguments. ok if you assume God exists as described in the bible then unless you're a fan of eternal "punishment" (various interpretations here left aside) it would be wise to fear him as it would be wise to fear a box jelly fish.

I think the more interesting question would be... if God exists why would he want you to fear him... one obvious answer would be that he loves people and would rather not have to "punish" them in keeping w/ his just character.

Fear is the "beginning" of wisdom hopefully not the culmination one might argue