There are typically two types of evidence that theists will cite in order to indicate the existence of a God: the material and the immaterial.
The first of these arguments is from science. Science, theists will say, shows that time and space is finite and had a beginning point. All things that begin to exist have an explanation for their existence. Since the cause of the universe is neither temporal nor material, it must be immaterial and eternal. Ala God.
Theists will also argue that the tremendous organization of the universe, including well established laws of physics, and enormous complexity both at the micro and macroscopic scale, and most especially the existence of living things – all with tremendous amounts of information encoded in their DNA – cannot be explained to have arisen by mindless chaos. Organization requires an organizer. Information requires a mind.
All of these are offered as evidence for the existence of a theistic deity; an intelligent designer.
This particular type of evidence is dismissed out of hand by the skeptical community. The mechanics of the universe are almost fully understood. It is a self contained machine. Just because there are one or two points on which science has not yet formed a robust theory does not make it permissible to cram God into that point as an explanation, and expect it to stick. Eventually science will be able to explain just exactly how the universe, laws of physics, and life forms came into existence without appealing to an outside agent, and then this kind of reasoning ceases to be able to rise to the level of “evidence” for God.
The second type of evidence to which theists will appeal are those things that exist outside the scope of science: the miraculous. God, they will argue, has acted in miraculous ways at various points in history. These actions that are contrary to what can be explained scientifically indicate that there exists some being who is superior to the laws of nature and can overrule them if he so chooses.
The problem with miracles, however, is that if “evidence” requires something that can be recorded and catalogued, miracles leave no such evidence behind. They tend to involve anecdotal evidence alone, which is notoriously unreliable, especially if the person in question has a bias to believe in the miraculous in the first place.
In a recent discussion on the show, “Unbelievable?”, skeptic Lawrence Krauss made the statement that if he were looking at the night sky, and the stars were to re-align to spell out in Aramaic or Hebrew or some such language “I am here,” then he might consider that theism has some explanatory power. Asked the question “Is there anything that might convince you God exists,” atheist proponent Justin Schieber made a similar comment in a recent broadcast of his show “Reasonable Doubts.”
Imagine for a moment that this exact thing were to happen. At his home in Washington State, Lawrence Krauss observes the stars re-align to spell out “I am here.” This particular evidence for God’s existence cannot hold up under the same criticisms that Krauss himself has expressed for other theistic proofs.
First of all, the fact that the stars re-aligned themselves in such a manner may not have an immediate scientific explanation, but this does not mean that one can simply attribute it to God. One must first explore the naturalistic explanations.
Moreover, this message is not accessible to the majority of the people on earth. No people in the southern hemisphere would be able to see it. This message could not be read by anyone who does not know the language in which it is written, nor could it be perceived by the blind, the illiterate, the mentally deficient, or non-human animals of any kind.
It would also be arrogant to suggest that human beings occupy a privileged position in the universe. From any other planet, this alignment of the stars would have no intelligible design to it. And besides, the act of re-aligning the stars would be a tremendously wasteful way of communicating, and would cause drastic gravitational shifts that would have repercussions throughout a large section of the galaxy, causing potential damage to any alien life forms on other planets.
Even if one were to accept that a god of some kind spelled this message out, this does nothing to tell which god is there. Is it Thor, Zeus, Quetzalcoatl, Allah?
Such dodges might appear ridiculous given the compelling nature of such a sign, but consider this:
Human beings around the planet all have an innate concept of right and wrong, and a concept of morality to go along with it. This, however, suffers from the same criticisms as Krauss’ star-message: moral codes vary according to culture. The mentally deficient, very young children, psychopaths, and certain animals have no access to moral law. Moral law is not a concept that can be proven scientifically; therefore it must not qualify as evidence.
Ask any intelligible human being anywhere on the planet, and they will have some concept of a god. Same criticisms: not everyone believes in god, even though they have that concept. God differs in characteristics according to culture. There is no way to know if mentally deficient, very young children, or animals have a concept of god. The idea of god is not something that can be proven scientifically; therefore this suspiciously universal concept must not qualify as evidence.
The universe is mind-bogglingly complex and ordered. Human DNA contains 700 terabytes of information. The massive, beautifully organized universe is intelligible specifically to human beings and not to all other known forms of life. Humans live, no matter which way one views it, in a privileged place in a delicately balanced eco system wrapped inside a delicately balanced solar system, contained in a delicately balanced galaxy.
Unlike a message written in a specific language viewable only from a certain spot in the universe, the amount of intelligible information contained in the universe (including the stunning beauty of the stars in the night sky) is perceivable from anywhere within the universe, and the more science digs, the more information is discovered.
This, of course, cannot qualify as evidence because the human mind is programmed to make order and perceives intelligibility wherever it looks, therefore order and intelligibility must be an illusion.
If God did, indeed, exist, it is difficult to know any way in which he could reveal his presence that could not be dismissed by such arguments. Any positive statement can be challenged by excuses and dismissals, but this does not qualify as a fair and rational consideration of evidence.