Debator seem to miss the obvious point that if i "reject" god, i dont expect him to "save my children", because i just dont think he exist.
I can, though, assume God exist and see if i derive contradictions in eg. the old testemony, just as debator can assume other Gods exist and point out cruelty in other non-christian religions. Its a method of argument that has been known since the ancient greek.
Caliber, the argument has several problems. For starters, you require "objective moral values". I dont postulate i have objective moral values, I just have a bag of things i find evil and good and which i operate within. This is things like Rape, Murder, Generosity, etc. Before you even have an argument, you need a definition of these objective moral values.
Secondly, why is God required for objective moral values (which i dont know what is)? He is certainly not required to understand why murder, rape or generocity is wrong/good - evolution and game theory can handle these very well! - and if we take those away, what is left which is objective and cannot be explained through biology? Furthermore, what if God was 80% cruel and 20% good and a bit manipulative, would we notice?
As i see it, you have not defined the central concept (objective moral values), nor have you provided evidence for premise 1 and 2.