One of the arguments creationists use on occasion to justify their belief in the Bible is that a society that doesn’t have a religious book that forms the basis for their moral values then that society will descend into some sort of a moral pit. Murder, robbery and rape will run rampant.
Putting their argument another way, even if evolution is scientifically valid they say that we shouldn’t acknowledge that because of the very immoral society that will necessarily result if that society’s religious book – e.g. the Bible – is discarded as not God’s Word.
Often those people will argue that evolution will encourage atheism and atheism will reduce the moral values in a society. So the acceptance of evolution is a stepping-stone to atheism. They believe that atheism is morally bad and so evolution is sort of an enabler of moral evils even if it is not the direct cause.
One example of the use of that argument comes directly from a religious leader:
“Evolution is the foundation of an immoral worldview.”
That argument is rampant with logical flaws.
First of all, history demonstrates that the acceptance of scientific facts doesn’t necessarily diminish the influence of the Bible.
Prior to, and during the Reformation in Europe, all Christian theologians interpreted the Bible as saying that the universe is centered on Earth – geocentrism. In the 21st century it is difficult to understand the theological importance of that.
The Earth was considered to be a very special place since it was where God put creatures “made in his image”. That is a self-evident fact if the Earth is, indeed, at the geometric center of the universe.
However that is much less obvious if, instead, the Earth is a mid-sized planet going around a mediocre star in an obscure part of a galaxy with many billions of similar stars within a larger universe with many billions of similar galaxies. Those conditions make it much less likely that the Earth is the “special place” that the Bible says it is.
Yet now, there is very little argument in favor of geocentrism. The scientific facts are so persuasive that no significant theologians still argue in favor of the argument for the Earth being at the center of the universe.
So this is an example of a scientific fact that was initially thought to go against the Bible and even against significant theological claims. That fact is now widely accepted. Has that eliminated the influence of the Bible on our society?
Hardly. Theologians adapted their beliefs. They found ways to reconcile the Bible with science.
There would seem to be no doubt that the same thing can happen with evolution. Some theologians have already made that accommodation. In fact some theologians welcomed Darwinian evolution when that idea was first presented to them.
Francisco Ayala, a Roman Catholic theologian as well as a respected scientist, put it like this:
“Traditional theology distinguishes three kinds of evil; moral or sin, the evil originated by human beings. Pain and suffering as experienced by humans. And physical evil such as floods, tornados, earthquakes and the imperfections of all creatures.
“Theology has an answer for the first 2; sin I a consequence of free will. Pain and suffering are caused by war, injustice and other forms of human wrong doing, they are also a consequence of free will; people choose to inflict harm on one another. On the flip side, good deeds people do can alleviate human suffering.
“What about natural disasters? Enter modern science into the theologians reasoning. Physical events are built on the structure of the world itself. The extreme violence of supernova explosions and chaotic frenzy at galactic centers are the outcome of the laws of physics, not the design of a fearsome deity. If God is the designer o life, whence the lion's cruelty, the snake's poison, and the parasites that secure their existence only by destroying their host?
“The theory of evolution provided the solution to the remaining component of the problem of evil. As floods and drought were a necessary consequence of the fabric of the physical world, predators and parasites, dysfunctions and diseases were a consequence of the evolution of life. They were not a result of deficient or malevolent design: the features of organisms were not designed by the Creator.
"Evolution by natural selection is Darwin's answer to Paley. It is also the solution of the last prong of the problem of evil. Theology professors in Salamanca saw in the theory of evolution a significant, even definitive, contribution to theodicy.”
So there seems to be no doubt that evolution can be adapted to Christian theology in the same way that geocentrism was.
The second argument against the claim that acceptance of evolution by a society will diminish moral values is that, if that is true, we should be able to see some evidence of that since there are currently a lot of people who believe in evolution.
Of course it’s difficult to quantify “morality” and therefore find statistics that could be used to compare moral values between different groups. One statistic that could be used involves crime rates. It seems reasonable that higher crime rates, particularly violent crime rates, would tend to be an indication of lower moral values.
It’s difficult to find statistics relating a belief in evolution to crime rates. But there are numerous statistics relating atheism to crime rates. There is, in fact, a correlation between a belief in evolution and atheism. (It is obviously an oxymoron to have an atheist believe in an inerrant Bible.) And, in fact, creationists are implying that evolution leads to atheism and atheism is the cause of a diminishment of moral values. So we should be able to relevantly compare atheism to crime rates and get some sense of whether or not a belief in evolution / atheism does indeed diminish moral values.
It turns out that does not seem to be the case as a number of statistics show otherwise.
Atheists are very much under-represented in prisons. In the United States, atheists make up roughly 10% of the general population but less than 1% of the prison population.
From country-to-country, there is a strong correlation between a high level of atheism and a lower crime rate. “Japan (the most atheistic nation in the G-8) has the lowest murder rate while the United States (the most Christian nation in the G-8) has the highest. Japan used to have much stronger religious faith, and a state religion, and guess what: Japan was remarkably aggressive and militaristic when "Shinto" was at its peak, and during WW2, when its Emperor was regarded as a God.
We see a similar trend in states of the United States. “Louisiana, with America's highest church attendance rate, has twice the national average murder rate.”
In fact, there seems to be no evidence that atheism – and implicitly a belief in evolution – lower moral levels in a society. If anything we see that the evidence points in the other direction.
Some people argue that it is religion based on a holy book that causes more evil than anything else. That argument is, I believe, best made by the physicist Dr. Victor J. Stengler:
“Theists try to counter all this [claims that religion causes immoral behavior] by pointing to the mass-murdering atheists of the twentieth century: Stalin, Mao, Pol Pot, Nicolae Ceaucesco, Enver Hoxa and Kim Jong-Il, as if this somehow justifies the religious mass murders that they can hardly deny. Hitler is usually included in that list, but he was a Catholic. Indeed the Roman Catholic Church never excommunicated a single Nazi but in 2010 it excommunicated nun Margaret McBride for allowing an abortion that was necessary to save the life of a pregnant woman suffering from pulmonary hypertension.
“Religion scholar Hector Avalon has studied documents from the Stalin era that only became recently available. He points out that there in no documented statement in which Stalin justified his actions by saying something such as, ‘I don’t believe in God therefore I am committing violent act X’. On the other hand, in all of the examples we saw above of terrorists associated with religion, you can find direct statements of the form, ‘God wants X, therefore I am committing violent act Y. Avalon says, ‘We cannot find any direct evidence that Stalin’s personal agenda killed because of atheism’.
“Now you might argue that while Stalin did not kill in the name of atheism, his godlessness failed to promote any restraint on his behavior. But then, neither has godliness provided much constraint to the murderers of history.”
This is not to say that religion causes immoral behavior directly. But it does show that atheism – and implicitly a belief in evolution – does not cause immoral behavior. So such arguments are fallacious.
 Moon, Rev. Sun Myung. 1990 (27 Mar.). Parents day and I. http://www.unification.net/1990/900327.html
 "Darwin's Gift To Science and Religion", p. 4-5
 http://atheism.about.com/b/2004/12/26/atheism-theism-and-violence.htm, referenced on April 16, 2012
 This particular statistic may have many other explanations. For example, it is possible that prison inmates who self-identify as atheists may lose rights or be subject to attacks by non-atheist inmates. They may even lose out on some of the rare social activities that take place in prison.
 “God and the Folly of Faith”, Prometheus Books, 2012, pp.255-256