Philosopher Blaise Pascal claimed that without God, people would only be able to create obstacles and overcome them in an attempt to escape boredom. These token victories would ultimately become meaningless, since people would eventually die, and this was good enough reason not to become an atheist. A number of religions also suggest that atheism has highly negative effects on the individuals after death: a point taken up by Pascal in Pascal's Wager (see picture and caption).
Christian author Alister McGrath has criticized atheism, citing studies suggesting religion and belief in God are correlated with improved individual health, happiness and life expectancy. However, atheists Gregory Paul and Michael Martin state that health, life expectancy and other factors of wealth are generally higher in countries with many atheists than in more religious countries.
There are additionally those who argue that the specific type of individuality required by atheism is a nearly impossible burden on the individual. Albert Camus is associated with this position, noting that this form of independence is "painful."
Many world religions teach that morality is derived from or expressed by the dictates or commandments of a particular deity, and that acknowledgment of God or the gods is a major factor in motivating people towards moral behavior. Consequently, atheists have frequently been accused of holding no rational basis for acting morally. For example, for many years in the United States, atheists were not allowed to testify in court because it was believed that an atheist would have no reason to tell the truth (see also discrimination against atheists).
Historically, practical atheism or apatheism - which describes individuals who live as if there are no gods and explain natural phenomena without resorting to the divine - has been associated with depravity, willful ignorance and impiety. Those considered practical atheists were said to behave as though God, ethics and social responsibility did not exist; they abandoned duty and embraced hedonism. According to the French Catholic philosopher Étienne Borne, "Practical atheism is not the denial of the existence of God, but complete godlessness of action; it is a moral evil, implying not the denial of the absolute validity of the moral law but simply rebellion against that law."
Some moral judgments of atheists do tend to differ from those of theists. A 2003 survey in the United States by The Barna Group found that those who described themselves as atheists or agnostics were more likely than theists to consider the following behaviors morally acceptable: cohabitating with someone of the opposite sex outside of marriage; enjoying sexual fantasies; having an abortion; sexual relationships outside of marriage; gambling; pornography; using drugs not prescribed by a doctor; getting drunk; and homosexuality.
Catholic and some secular intellectuals attribute the perceived post-war decadence of Europe to the displacement of absolute values by moral relativism. Pope Benedict XVI, Marcello Pera and others have argued that after about 1960, Europeans massively abandoned many traditional norms rooted in Christianity and replaced them with continuously-evolving relative moral rules. In this view, sexual activity has become separated from procreation, which led to a decline in the importance of families and to depopulation. As a result, currently the population vacuum in Europe is filled by immigrants, often from Islamic countries, who attempt to reestablish absolute values which stand at odds with moral relativism. The most authoritative response to moral relativism from the Roman Catholic perspective can be found in Veritatis Splendor, an encyclical by Pope John Paul II.
Many among theists and atheists do not believe that theism, or lack of it, has any pronounced effect on whether a person behaves morally or not. For instance, the Dalai Lama has said that compassion and affection are human values independent of religion:
The notion that atheists are able to live ethical lives may be supported by the traditional Christian concept of natural law. According to the Catholic Church; the human reason inclines people to seek the good and avoid sin, and that people would therefore still be prone to moral behavior even without knowledge of a revealed divine law. This natural law would provide a foundation on which people could build moral rules to guide their choices and regulate society, but would not provide as strong a basis for moral behavior. Other Christian groups adopt similar reasoning. Douglas Wilson argues that while atheists can behave morally, belief is necessary for an individual "to give a rational and coherent account" of why they are obligated to lead a morally responsible life. As he puts it, atheism is unable to "give an account of why one deed should be seen as good and another as evil" (emphasis in original).
At times, this argument consists of laying the burden of proof on atheism, or in the case of agnostics and weak atheists, laying it on both strong atheism and theism. However, laying the burden of proof on atheism may be difficult because it is impossible to prove a universal negative existential claim unless what is claimed to exist cannot logically be. While it might be theoretically possible to one day find reasonably persuasive evidence of the existence of a deity, it is impossible to find evidence of any thing's nonexistence. As such, arguments for strong atheism consist primarily of arguments against theism, which is in keeping with claims that atheism in general is only the lack of a belief rather than a belief itself. Some strong atheists argue that, since they see the burden of proof as being upon theism, they are under no obligation to offer arguments that seek to actively disprove theism. Instead, strong atheism is a default position, like disbelief in Santa Claus, that they feel ought to be held unless and until that burden of proof is shouldered. However, weak atheists and agnostics feel that neither theism nor strong atheism are a proper default position to be taken and hence labelling both theism's and strong atheism's calls for proof to be argumentum ad ignorantiam.
There has been a push in certain philosophical circles to redefine atheism as the "absence of belief in deities", rather than as a belief in its own right; this definition has become popular in atheist communities, though its mainstream usage has been limited. Thus, one atheistic response is to emphasize that (weak) atheism is a rejection or lack of belief, not a belief in itself. This argument is often summarized by reference to Don Hirschberg's famous saying, "calling atheism a religion is like calling bald a hair color.
Another atheistic response to this argument is to state that the word "faith" in this context, as asserted with respect to theist "belief" versus atheist "belief," means something very different in the two contexts. Faith can mean 'complete confidence in a person or plan, etc.' Faith can also mean 'Belief that does not rest on logical proof or material evidence'. When a theist speaks of his faith, it is argued, he refers to the latter definitions. When he wishes to assert that "atheists have faith, too", the only definition that fits is the first, but his argument implies the latter definitions, nonetheless (see equivocation).
Some people have, in response to this argument, drawn the analogy of Russell's teapot.
In The New Inquisition, Robert Anton Wilson lampoons the members of skeptical organizations like the Committee for the Scientific Investigation of Claims of the Paranormal (CSICOP - now the Committee for Skeptical Inquiry) as fundamentalist materialists, alleging that they dogmatically dismiss any evidence that conflicts with materialism as hallucination or fraud. Michael Novak, reviewing books by Sam Harris, Daniel C. Dennett and Richard Dawkins in National Review, writes that "all three pretend that atheists 'question everything' and 'submit to relentless, almost tedious, self-criticism.' Yet in these books there is not a shred of evidence that their authors have ever had any doubts whatever about the rightness of their own atheism.
Richard Dawkins has stated, "Passion for passion, an evangelical Christian and I may be evenly matched. But we are not equally fundamentalist. The true scientist, however passionately he may 'believe', in evolution for example, knows exactly what would change his mind: evidence! The fundamentalist knows that nothing will.
Atheism has a comparatively small public voice, but it is a voice that many believers hear. However, when they listen to this voice, they often hear little more than slurs and insults. When interacting with atheists, believers are frequently met with the same arrogance and condescension, the same hatred and vitriol, the same bigotry and prejudice, as atheists so often receive from believers. In short, believers tend to encounter in atheists exactly what they have been taught to expect.
Sam Harris has been criticized by some of his fellow contributors at The Huffington Post. In particular, RJ Eskow has accused him of fostering an intolerance towards faith, potentially as damaging as the religious fanaticism which he opposes. Madeleine Bunting writes in The Guardian that the purpose of recent books by Richard Dawkins, Daniel Dennett, Sam Harris and Christopher Hitchens "is to pour scorn on religious belief - they want it eradicated," and argues that the books are "deeply political," sharing a "loathing" of the role of religion in US politics. Quoting Harris as saying "some propositions are so dangerous that it may even be ethical to kill people for believing them," Bunting says "[t]his sounds like exactly the kind of argument put forward by those who ran the Inquisition.
In December 2007, the Archbishop of Wales Barry Morgan criticized what he referred to as "atheistic fundamentalism", claiming that it advocated that religion has no substance and "that faith has no value and is superstitious nonsense. He claimed it led to situations such as councils calling Christmas "Winterval", schools refusing to put on nativity plays and crosses removed from chapels, though others have disputed this.
As a theistic religion, Christianity necessarily rejects atheism. While the Catechism of the Catholic Church identifies atheism as a violation of the First Commandment, calling it "a sin against the virtue of religion", it is careful to acknowledge that atheism may be motivated by virtuous or moral considerations, and admonishes the followers of Roman Catholicism to focus on their own role in encouraging atheism by their religious or moral shortcomings:
According to historian Michael Burleigh, antitheism found its first mass expression in revolutionary France in response to organized resistance to "organised ... irreligion...an 'anti-clerical' and self-styled 'non-religious' state. In Soviet Russia the Bolsheviks originally embraced "an ideological creed which professed that all religion would atrophy" and "resolved to eradicate Christianity as such." In 1918 "Ten Orthodox hierarchs were summarily shot" and "Children were deprived of any religious education outside the home. Increasingly draconian measures were employed. In addition to direct state persecution, the League of the Militant Godless was founded in 1925, churches were closed and vandalized and "by 1938 eighty bishops had lost their lives, while thousands of clerics were sent to ... labour camps.
Christian writer Dinesh D'Souza writes that "The crimes of atheism have generally been perpetrated through a hubristic ideology that sees man, not God, as the creator of values. Using the latest techniques of science and technology, man seeks to displace God and create a secular utopia here on earth." He also contends:
In response to such criticism, atheist writer Sam Harris writes:
Richard Dawkins has stated that Stalin's atrocities were influenced not by atheism but by their dogmatic Marxism, and opines that while Stalin and Mao happened to be atheists, they did not do their deeds in the name of atheism.
There have been cases, however, of regimes specifically targeting religion for the purpose of spreading atheism; for example, in 1967, Enver Hoxha's regime conducted a violent campaign to extinguish religious life in Albania; by year's end over two thousand religious buildings were closed or converted to other uses, and religious leaders were imprisoned and executed. Albania was declared to be the world's first atheist country by its leaders, and Article 37 of the Albanian constitution of 1976 stated that "The State recognises no religion, and supports and carries out atheistic propaganda in order to implant a scientific materialistic world outlook in people.