August Berkshire, the public relations representative for Minnesota Atheists and Vice-President of Atheist Alliance International, has put together a simple, concise list of 21 Unconvincing Arguments for God (PDF).

Here's his list:

(1) Holy Books - Just because something is written down does not make it true. This goes for the Bible, the Qu’ran, and any other holy book. It is circular reasoning to try to prove the god of a holy book exists by using the holy book itself as “evidence.”

People who believe the holy book of one religion usually disbelieve the holy books of other religions.

(2) “Revelations” - All religions claim to be revealed, usually through people called “prophets.” But a revelation is a personal experience. Even if the revelations really did come from a god, there is no way we could prove it. As Thomas Paine said, it is a revelation only to the first person, after that it is hearsay. People of one religion usually disbelieve the revelations of other religions.

(3) Personal Testimony / Feelings - This is when you are personally having the revelation or feeling that a god exists. Though you may be sincere, and even if a god really does exist, a feeling is not proof, either for you or for someone else.

(4) The “God Part” of the Brain - Some religious people argue that a god must exist, or why else would we have a part of our brain that can “recognize” a god? What use would that part of our brain be otherwise?

However, imagination is important for us to be able to predict the future, and thus aids our survival. We can imagine all kinds of things that aren’t true. It is a byproduct of being able to imagine things that might be true.

As a matter of fact, scientists have begun to study why some people have religious beliefs and others don’t, from a biological perspective. They have identified certain naturally occurring chemicals in our brains that can give us religious experiences.

In studies of religion and the brain, a new field called neurotheology, they have identified the temporal lobe as a place in the brain that can generate religious experiences.

Another part of the brain that regulates a person’s sense of “self” can be consciously shut down during meditation, giving the meditator (who loses his or her sense of personal boundaries) a feeling of “oneness” with the universe.

(5) “Open Heart” - It will do no good to ask atheists to “open our hearts and accept Jesus” (or any other deity). If we were to set aside our skepticism, we might indeed have an inspirational experience. But this would be an emotional experience and, like a revelation, we’d have no way to verify if a god was really speaking to us or if we were just hallucinating.

(6) Unverifiable “Miracles” / Resurrection Stories - Many religions have miracle stories. And just as people who believe in one religion are usually skeptical towards miracle stories of other religions, atheists are skeptical toward all miracle stories.

Good magicians can perform acts that seem like miracles. Things can be mismeasured and misinterpreted. A “medical miracle” can simply be attributed to our lack of knowledge of how the human body works. Why are there never any indisputable miracles, such as an amputated arm regenerating?

Regarding resurrections, atheists will not find a story of someone resurrecting from the dead to be convincing. There are many such legends in ancient literature and, again, most religious people reject the resurrection stories of other religions.

Modern resurrection stories always seem to occur in Third World countries under unscientific conditions. However, there have been thousands of people in modern hospitals hooked up to machines that verified their deaths when they died. Why didn’t any of them ever resurrect?

(7) Fear of Death / “Heaven” - Atheists don’t like the fact that we’re all going to die any more than religious people do. However, this fear does not prove there is an afterlife – only that we wish there was an afterlife. But wishing doesn’t make it so.

There is no reason to believe our consciousness survives the death of our brains. The mind is not something separate from the body. Chemical alteration and physical damage to our brains can change our thoughts.

Some people get Alzheimer’s disease at the end of their lives. The irreversible damage to their brains can be detected by brain scans. These people lose their ability to think, yet they are still alive. How, one second after these people die, does their thinking return (in a “soul”)?

(8) Fear of Hell - The idea of hell strikes atheists as a scam – an attempt to get people to believe through fear what they cannot believe through reason and evidence.

The only way to approach this “logically” is to find the religion that punishes you the worst for disbelief, and then believe that religion. Okay, you will have saved yourself from the worst punishment that exists – if that religion is the “true” religion.

But if that religion (with its punishment) is not the true religion – if the religion that has the second or third worst punishment for disbelief is the true religion – then you have saved yourself nothing.

So, which religion’s hell is the true hell. Without evidence, we can never know.

(9) “Pascal’s Wager” / Faith - In short, Pascal’s Wager states that we have everything to gain (an eternity in heaven) and nothing to lose by believing in a god. On the other hand, disbelief can lead to a loss of heaven (i.e. hell).

We’ve already noted that heaven is wishful thinking and that hell is a scam, so let’s address the issue of faith.

Pascal’s Wager assumes a person can will himself or herself into having faith. This is simply not the case, at least not for an atheist. So atheists would have to pretend to believe. But according to most definitions of God, wouldn’t God know we were lying to hedge our bets? Would a god reward this?

Part of Pascal’s Wager states that you “lose nothing” by believing. But an atheist would disagree. By believing under these conditions, you’re acknowledging that you’re willing to accept some things on faith. In other words, you’re saying you’re willing to abandon evidence as your standard for judging reality. Faith doesn’t sound so appealing when it’s phrased that way, does it?

(10) Blaming the Victim - Many religions punish people for disbelief. However, belief requires faith, and some people, such as atheists, are incapable of faith. Their minds are only receptive to evidence. Therefore, are atheists to be blamed for not believing when “God” provides insufficient evidence?

(11) The End of the World - Like the concept of hell, this strikes atheists as a scare tactic to get people to believe through fear what they can’t believe through reason and evidence. There have been predictions that the world was going to end for centuries now. The question you might want to ask yourselves, if you’re basing your religious beliefs on this, is how long you’re willing to wait – what amount of time will convince you that the world is not going to end?

(12) Meaning in Life - This is the idea that, without belief in a god, life would be meaningless. Even if this were true, it would only prove we wanted a god to exist to give meaning to our lives, not that a god actually does exist. But the very fact that atheists can find meaning in their lives without a belief in a god shows that god belief is not necessary.

(13) “God is Intangible, Like Love” - Love is not intangible. We can define love both as a type of feeling and as demonstrated by certain types of actions.

Unlike “God,” love is a physical thing. We know the chemicals responsible for the feeling of love.

Also, love depends upon brain structure – a person with a lobotomy or other type of brain damage cannot feel love.

Furthermore, if love were not physical, it would not be confined to our physical brains. We would expect to be able to detect an entity or force called “love” floating around in the air.

(14) Morality/Ethics - This is the idea that without a god we’d have no basis for morality. However, a secular moral code existed before the Bible: the Code of Hammurabi.

In Plato’s dialogue called Euthyphro, Socrates asks a man named Euthyphro whether something is good because God says it is, or does God announce something to be good because it has intrinsic goodness?

If something is good because God says it is, then God might change his mind about what is good. Thus, there would be no absolute morality.

If God merely announces something to be good because it has intrinsic goodness, then we might be able to discover this intrinsic goodness ourselves, without the need for god belief.

Christians can’t even agree among themselves what’s moral when it comes to things like masturbation, premarital sex, homosexuality, divorce, contraception, abortion, embryonic stem cell research, euthanasia, and the death penalty.

Christians reject some of the moral laws found in the Bible, such as killing disobedient children or people who work on the sabbath. Therefore, Christians must be applying their own ethical standards from outside the Bible to be able to recognize that these commandments in the Bible are unethical.

Other animals exhibit kindness toward one another and a sense of justice. Morality is something that evolved from us being social beings. It’s based on the selfish advantage we get from cooperation, and on consequences.

(15) Altruism - People sometimes say that without a god there would be no altruism, that evolution only rewards selfish behavior.

However, it can be argued that there is no such thing as altruism, that people always do what they want to do. If they are only faced with bad choices, then people choose the thing they hate the least.

Our choices are based on what gives us (our genes) the best advantage for survival, including raising our reputation in society.

“Altruism” towards family members benefits people who share our genes. “Altruism” towards friends benefits people who may someday return the favor.

Even “altruism” towards strangers has a basis in evolution. This behavior first evolved in small tribes, where everyone knew each other and a good reputation enhanced one’s survival. It is now hard-wired in our brains as a general mode of conduct.

(16) Free Will - Some people argue that without a god there would be no free will, that we would live in a deterministic universe of cause and effect and that we would be mere “robots.”

Actually, there is far less free will than most people think there is. Our conditioning (our biological desire to survive and prosper, combined with our experiences) make certain “choices” far more likely than others. How else can we explain our ability, in many cases, to predict human behavior?

Experiments have shown that our brain makes a “decision” to take action before we become conscious of it!

Some believe that the only free will we have is to exercise a conscious veto over actions suggested by our thoughts.

Most atheists have no problem admitting that free will may be an illusion.

This issue also brings up a conundrum: If a god who created us knows the future, how can we have free will?

In the end, if we are enjoying our lives, does it matter if free will is real or an illusion? Isn’t it only our ego – our healthy self-esteem that is beneficial for survival – that has been conditioned to believe that real free will is somehow better than imaginary free will?

(17) Difficulties of Religion - It has sometimes been argued that because certain religious practices are difficult to follow, nobody would do them if a god didn’t exist. However, it is the belief in the existence of a god that is motivating people. A god doesn’t really have to exist for this to happen.

Difficulties can serve as an initiation rite of passage into being counted one of the “select few.” After all, if just anybody could be “saved,” there might be no point in having a religion.

Finally, the reward for obedience promised by most religions – a heaven – far outweighs any difficulties religion imposes.

(18) False Dichotomies - This is being presented with a false “either/or” proposition, where you’re only given two alternatives when, in fact, there are more possibilities.

Here’s one that many Christians are familiar with: “Either Jesus was insane or he was god. Since Jesus said some wise things, he wasn’t insane. Therefore, he must be God, like he said he was.” But those are not the only two possibilities.

A third option is that, yes, it is possible to say some wise things and be deluded that you are a god.

A fourth possibility is that Jesus didn’t say everything that is attributed to him in the Bible. Maybe he didn’t actually say all those wise things, but the writers of the Bible said he did. Or maybe he never claimed to be God, but the writers turned him into a god after he died.

A fifth possibility is that Jesus is a fictional character and so everything was invented by the authors.

Here’s another example of a false dichotomy: “No one would die for a lie. The early Christians died for Christianity. Therefore, Christianity must be true.”

What’s left out of this is that there is no evidence that anyone who ever personally knew Jesus (if he even existed) was ever martyred. We only have stories of martyrdom.

Another explanation is that the followers had been fooled, intentionally or unintentionally, into thinking Jesus was God, and so they were willing to die for a lie (that they thought was true.)

Another point is that if you believe you’ll end up in a heaven after to die, then martyrdom is no big deal.

Finally, does the fact that the 9/11 bombers were willing to die for their faith make Islam true?

(19) God-of-the-Gaps (Medicine, Life, Universe, etc.) - The god-of-the-gaps argument says that if we don’t currently know the scientific answer to something, then “God did it.”

God-of-the-gaps is used in many areas, but I’ll focus on the three main ones: medicine, life, and the universe. You’ll notice that God never has to prove himself in these arguments. It is always assumed that he gets to win by default.

Here’s a medical example: A person experiences a cure for a disease that science can’t explain. Therefore, “God did it.”

But this assumes we know everything about the human body, so that a natural explanation is impossible. But the fact is, we don’t have complete medical knowledge. Why don’t we ever see something that would be a true miracle, like an amputated arm instantaneously regenerating?

Several studies of prayer, where the patients didn’t know whether or not they were being prayed for, including a study by the Mayo Clinic, have shown prayer to have no effect on healing.

(This raises the question of why we would have to beg an all-powerful, all-loving god to be healed in the first place. It seems ironic, to say the least, to pray to a god to be cured from diseases and the effects of natural disasters that he himself created. It also raises the Problem of Evil: If God is all-powerful and all-loving, why does evil exist in the first place?)

An example of god-of-the-gaps as it applies to life is creationism and “intelligent design.” It says we don’t know everything about evolution, therefore “God did it.” This ignores the fossil and genetic evidence and also fails to explain the many poor and sub-optimal “designs” we find in nature. Is “God” an incompetent or sloppy designer?

The final and most popular example of god-of-the-gaps is the universe. But to say we don’t know the origins of the universe – if the universe even had an ultimate beginning – does not mean that “God did it.”

And, of course, it begs the question: Who created God? If complex things need a creator to explain their existence, then “God,” who by the traditional definition is far more complex than the universe, and is even more in need of a creator.

(20) “Fine-tuning” of the Earth - Some religious people argue that the Earth is positioned “just right” in the solar system (not too hot, not too cold, etc.) for life to exist. Furthermore, the elements on Earth (carbon, oxygen, etc.) are also “just right.” These people claim that this couldn’t have happened “by accident,” so a god must exist to have done the positioning and chemistry.

We should be able to recognize a god-of-the-gaps argument here. But an even better rebuttal exists. If Earth was the only planet in the universe, then it would indeed be remarkable that our conditions turned out to be “just right.”

But most religious people acknowledge that there are probably thousands, if not millions, of other planets in the universe. (Our own solar system has eight planets.) Therefore, by chance, at least one of those planets will have conditions that will produce some kind of life.

We can imagine religious purple creatures with four eyes and breathing carbon dioxide on another planet also falsely believing that their planet is “fine-tuned” and that a creator god exists in their image.

(21)“Fine-tuning” of the Universe - Some religious people argue that the six physical constants of the universe (which control such things as the strength of gravity) can only exist within a very narrow range to produce a universe capable of sustaining life. Therefore, since this couldn’t have happened “by accident,” a god must have done it.

Again, this is a god-of-the-gaps argument. But beyond that, this argument assumes that we know everything about astrophysics – a field in which new discoveries are made on almost a daily basis. We may discover that our universe is not so “fine tuned” after all.

However, the best rebuttal is that there may exist multiple universes – either separately or as “bubble universes” within a single universe. Each of these universes could have its own set of constants. Given enough universes, by chance it is likely that at least one will produce and sustain life.

We know it is possible for at least one universe to exist – we are in it. If one can exist, why not many? On the other hand, we have no evidence that it is possible for even one god to exist.

Conclusion - Religious people have a tough, if not impossible task to try to prove a god exists, let alone that their particular religion is true. If any religion had objective standards, wouldn’t everyone be flocking to the same “true” religion? Instead we find that people tend to believe, to varying degrees, the religion in which they were indoctrinated. Or they are atheists.