The moral choice

This post regards the origin of religion. Where does morality come from and why should we follow it? Most people take this for granted. An action is either right or wrong and thats that. Most of agree that under most circumstances, killing another person is wrong. The question I want to answer is why? Why is this wrong? Why is anything wrong?
I`ve only managed to come up with two possible answers to this question. The first is the scientific answer, rooted in biology, and states that we act morally because we have evolved to act morally. If killing people of your own tribe was allowed, then it would be impossible for the members of that tribe to cooperate, and as a result, the tribe would weaken. In other words, morality is a form of social control mechanism rooted in our biology, part of our nature as tribal animals.
So, in the end, if each of us behaves morally, it benifits all, including ourselves. This means that all morality can be traced back to self interest. Killing someone will have negative social repercussions both on society and the murderer himself. Even if he isn`t caught, he will always have to live his life with part of himself hidden, because society does not approve of his actions. In a broader sense, killing contributes to social instability which in the end would lead to a weaker society compared to more stable ones, making it and everyone in it weaker and poorer.
This kind of morality works for all moral statements I have heard. It can be infinitely extended to include more people and more species. Cutting too many trees harms the ecosystem which we all need to survive, for example. So, this is indeede a complete and sound basis for a moral construct, and is in fact the way most people today instinctively think about morality. But this kind of morality has many flaws.
First, it puts the burden of proof on the side of good. An unwanted but very real effect of this way of thinking is that all actions are right until proven to be wrong. Cutting down a tree is not wrong in itself, but is perfectly fine until someone can prove to you that cutting that tree harms the ecosystem in some way.
If we could think that cutting down a tree, any tree, is in itself a morally wrong action, then the one who wishes to cut that tree must be the one to prove that cutting the tree is really necessary to him, for his survival or some such reason. But this way of thinking cannot be grounded in evolution. It is indeed benificial to our evolution to cut down trees!
The other major flaw in this way of thinking is that it is frankly, cynical. Compassion and love, which is more or less uniformly agreed to be the emotional basis of morality, seem entirely absent from this rational weighing of arguments and facts. You might say it is open to discussion wether such a bloodless way of thinking truly is morality at all!
So the alternative to this way of thinking must be to say that some things, some actions, are just wrong in their very nature. Much of western society and morality is based upon such a notion in fact. Take the American declaration of indipendence, which states that "We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness." We find similar ideas layed down in the UN`s declaration of human rights, and various other documents central to the shaping of euro-american civilization.
Through extention, these ideas could also come to include members of other species and societies, even plants. So, this also forms a complete and sound basis for an all-encompassing moral construct, while solving the problems connected to the biological approach sketched above. Problem solved, right?
No, we are left with our original question. Where do these rights come from? Why do we have those rights? It seems someone just decided we have them, and now we do. In our day, we take these rights for granted, we take morality for granted. If a moral statement cannot be explained through biology, then thats just the way it is. We learned that certain things were right and certain things were wrong as children, and it`s just always been like that.
That is not enough for me. I must ask why. And there can only be one answer. To those who wrote the american declaration of independence, the answer was self-evident, though people prefer to ignore that fact. Morality must, in the end, come from some non-physical source, some excistence that transcends the simple physical reality we see around us every day.
Morality must come from God.