I was browsing some christian forums when I found this piece. I didn't see any atheists actually reply to it though. (The site allows members of other faiths - or lack of) Well the guy who posted it really wanted to have atheists read it and respond (or, even better- convert). So I thought I'd post it here to gather the intended audience's thoughts/reactions/answers.
Having once been an atheist, I understand the mindset pretty well. Empirical evidence is the best thing to use in dialogue with an atheist or an agnostic. Educated atheists and agnostics will, for the most part, be utterly unresponsive to the gospel so long as intellectual barriers to faith remain. So in this thread I'd like to brainstorm some of the most effective arguments to use when dialoging with educated unbelievers. I'll start with a few and you can all add to them.
1. Fine tuning - the universe is highly finely tuned for the existence of intelligent life. The initial conditions of the big bang, which are not physically necessary but are simply given, are so utterly precise that to alter them by a tiny fraction of a percent would make life and even stars impossible. The fact that the universe just so happened to be finely tuned to allow for life, when it could have in theory been otherwise, points to an intelligent mind behind natural design.
2. The beginning - at a finite point in time, 13.7 billion years ago, the universe began to exist. The universe came to be, out of nothing, exactly as Genesis 1:1 declares. Something must be eternal, otherwise you run into the problem of an infinite regress. Either matter/energy is eternal, or something else is eternal. Matter/energy is not eternal, because it began to exist at the moment of the big bang. Therefore something else is eternal. Working with the evidence of fine tuning in the universe, we can infer that the eternal cause behind the universe must be intelligent, powerful, and intentional. Intelligence is needed to explain the ordered design of the universe, and power and intentionality are required to explain the creation of the universe. An eternal cause that is intelligent, powerful, and intentional is, by definition, God.
3. Human uniqueness - Human beings, though genetically very similar to other organisms, are vastly different from the rest of the animal kingdom. Unlike other animals, human beings posses a reflective and introspective self-awareness. Even if we allow for a purely Darwinian explanation for the development of life, the vast complexity of our unique human consciousness cannot be adequately explained. The bible, however, declares that we are made in the image of God and, hence, posses some of his attributes, albeit in drastically minimized form. If we accept this biblical premise as true, we would expect to find the human cognition utterly unique in the animal kingdom, which is exactly what we find. Even though we share 98% of our genes with chimpanzees, our cognition is dramatically more complex and is in fact indicative of transcendence. Add to all of this the omnipresence of spiritual belief in human societies throughout all of recorded history, and you have good empirical evidence for the uniqueness of the human mind. Given all of this, the biblical explanation for the novelty of the human consciousness has the best explanatory power and ought to be accepted as true.
4. Existence of Aesthetics - Humans are also unique in our recognition of and perception of beauty. When we look at the earth and the larger universe we are struck by a sense of wonder and an appreciation of beauty. What is beauty? Why is it that nature, as perceived through our senses, is pleasing to us? Certainly there is no Darwinian reason for the existence of aesthetics, for what differential reproductive benefit can such a thing bestow? The universe, it seems, is objectively beautiful, a fact that is hard to explain in a purely naturalistic and non-theistic framework. However the bible makes the claim that the universe declares the glory of God. Given this premise we would expect that our perception of nature would evoke feelings of wonder and awe, a sense of beauty and majesty, to point us toward the creator and a recognition of some of his attributes. Once again the biblical worldview explains the phenomena better than a naturalistic framework.
In furthering of your arguments:
1. The fact that in an obscure corner of a rather undistinguished galaxy life exists hardly argues for an entire universe finely tuned for mankind.
2. I don't know why theists go straight for the notion that some person made the cosmos rather than it simply happened for reasons unknown,
3. Every species is special (unique) in some way. That's what being a species is all about. If all critters were alike, there'd be no such thing as a species. "Special" and "species" obviously come from a common root word.
4. Someone who thinks animals have no aesthetic sense has never owned a cat. To see a cat stretched out in the sun on a sunny morning reveals an appreciation for the beauty of a dawning day which escapes many human beings.