The thing you need to realize about us "Nihilistic Cynicists" is that on the way to deciding that there probably isn't any ultimate point to many things, we spend a lot of time asking what the actual point IS.
In the case of what the point was for the origin of moral code, review post #6 (me) and post #12 (EDG). The point was that we do what we need to survive and that interactions with others have consequences. Not getting stomped into the mud by your fellow man requires adopting a certain set of behaviors. Not having your children get stomped into the mud by your fellow man requires imparting the rules for that set of behaviors. The smart adult figures out what is required by the situation and modifies his behavior, but his children are brainwashed into that behavior by whatever convincing fiction he decides to tell them (such as "because God said so"). So at it's core, morals could be said to come from various combinations of laziness, fear, and lack of physical prowess.
An example of the flip side of that might be Ghenghis Khan - certainly not lazy, didn't have cause to be afraid of much, and was able to take what he wanted to the extent that it's estimated that 1 in 200 men alive today (1 in 10 in Mongolia) are his descendant. When you're enough of a bad, bad donkey that you don't NEED to get along with your fellow man, you don't NEED to play by the significantly more touchy-feely rules that the rest of us do. Ghengis certainly qualified as a successful Darwinian Competitor. Most of us are conditioned to not instantly flock to his behavioral banner - we INSTINCTIVELY do, but since we don't all have Ghengis' magic combination of "herd bull" attributes, we don't typically act on those instincts for fear of the stomped-into-the-mud reasons mentioned above.
So here's a riddle for the framework of your Christian ethos: Ghengis Khan had his set of morals that kept him unquestionably "whole and prosperous". Is that the way God wanted him to be, and did he fulfill God's mandate? My point is that he managed to do quite well for himself on a code of being a ruthless tyrant and probably went to bed at night feeling quite good about it. For the rest of us, remaining whole and prosperous requires a very different behavior set that typically does NOT lead to 10% of the local population having your DNA a thousand years later. Given that, how do your reconcile the two? Does God want the lion or the sheep? I suspect you decide which you are by how frequently you find yourself covered in mud.