Fine Tuning: This argument (based on my understanding) is based on the assumption that life can only form under the conditions of our universe and only takes into account life as we know it. Is it not possible for life to form under different physical constants? If so, wouldn't the fine tuning of our universe be irrelevant to the question of God's existence?
Moral Argument: You assert that objective morality comes about through God (to put it very simply). Isn't it just as plausible to see morality as something evolving from early homo sapiens and the development of different societies and civilizations and the necessities that follow from living in those societies? Couldn't morality have come about naturally through the demands of a society to conform to the norms?
Dr. William Lane Craig responds:
1. Fine-Tuning. Your understanding of the argument is incorrect. See my exposition of the argument in Reasonable Faith, 3rd ed. When scientists talk about a universe's being life-permitting, they're not talking about just present forms of life. By "life" scientists just mean the property of organisms to take in food, extract energy from it, grow, adapt to their environment, and reproduce. Anything that can fulfill those functions counts as life. And the point is, in order for life so-defined to exist, whatever form it might take, the constants and quantities of the universe have to be unbelievably fine-tuned. You suggest that if the constants and quantities had had different values, then different forms of life might have evolved. But you're underestimating the truly disastrous consequences of a change in the values of these constants and quantities. In the absence of fine-tuning not even matter, not even chemistry, would exist, much less planets where life might evolve.
Someone might think, "But maybe in a universe governed by different laws of nature, such disastrous consequences might not result." But this objection also betrays a misunderstanding of the argument. We're not concerned with universes governed by different laws of nature. We have no idea what such universes might be like! Rather we're concerned solely with universes governed by the same laws of nature but with different values of the constants and arbitrary quantities. The philosopher John Leslie gives the following illustration: imagine a solitary fly, resting on a large, blank area of the wall. A single shot is fired, and the bullet strikes the fly. Now even if the rest of the wall outside the blank area is covered with flies, so that a randomly fired bullet would probably hit one, nevertheless it remains highly improbable that a single, randomly fired bullet would strike the solitary fly within the large, blank area.
In the same way, we need concern ourselves only with universes governed by the same laws of nature in order to determine how likely it is that one of them should be life-permitting. Because the laws are the same, we can determine what would happen if the constants and quantities were to be altered. And the results turn out to be disastrous. A life-permitting universe is like that solitary fly on the wall.
2. Morality. The answer to your questions is: It all depends! If God does not exist, then, as I've argued, what you say is exactly what moral values are: mere byproducts of biological and social evolution. But if God exists, then they're not. For the truth of a belief is independent of how you came to hold that belief. You may have acquired your moral beliefs through a fortune cookie or by reading tea leaves, and they could still be true. In particular, if God exists, then objective moral values and duties exist, regardless of how we come to learn about them. The socio-biological account at best proves that our perception of moral values and duties has evolved. But if moral values are gradually discovered, not invented, then our gradual and fallible perception of those values no more undermines their objective reality than our gradual, fallible perception of the physical world undermines its objective reality.
So the real question is: do you think there is an objective distinction between good and evil, right and wrong? I'm sure you do. Philosophers who reflect on our moral experience see no more reason to distrust that experience than the experience of our five senses. I believe what my five senses tell me, that there is a world of physical objects out there. Similarly, in the absence of some reason to distrust my moral experience, I should accept what it tells me, that some things are objectively good or evil, right or wrong.
Extracted from ReasonableFaith.org