I got hold of the book Cosmic Jackpot by Paul Davies. I'll focus on a very small section of it for the purpose of this post. In chapter 9 (Intelligent and Not-So-Intelligent Design) there is a subsection entitled God as a Necessary Being. In a somewhat unorthodox manner Davies broaches the who designed God or who designed the designer question. Davies correctly identifies God as having unique properties including an existence that is not owed to a preexisting cause. Davies then goes on to describe God as a necessary being making it logically impossible for God not to exist. Dwelling on the word necessarily, Davies cites God's choice to create the universe as logically problematic; asking if a necessary being can behave in a way that is not necessary?
Although generally a precise thinker Davies allows linguistic ambiguities to guide his own analysis. God's actions are not necessary in the sense that God's behavoir is predetermined by causal necessity. There is no reason to assume an absence of divine freedom of choice.
Logical difficulties are inherent with accounts of beginings- at least from the perspective of finite human minds. Conceptual difficulties are inherent to differing and conflicting accounts of origins. Those who find logical difficulties with a God, who preexists the universe, could find logical difficulties with alternative explanations if they look for them. For example, assume there is no God. There is, however, a universe and attempts to account for its existence lead to infinte regress arguments. If the universe is attributed to a big bang then what caused the big bang? If the big bang was preceeded by a singularity and specified conditions then what led to this and so on. When confronted with the alternative, a God who existed prior to and outside his created universe, no longer can be seen as entailing uniquely difficult conceptualizations.
Does all this mean we can know God through human reason alone? No, but God can and has revealed himself to us. The seal of credibility was the resurrection of the Son of Man.