Some movements or sects within traditionally monotheistic or polytheistic religions recognize that it is possible to practice religious faith, spirituality and adherence to tenets without a belief in deities. People with what would be considered religious or spiritual belief in a supernatural controlling power are defined by some as adherents to a religion; the argument that atheism is a religion has been described as a contradiction in terms.
Abrahamic religions
Judaism
In general, formulations of Jewish principles of faith require a belief in God (represented by Judaism's paramount prayer, the Shema). In many modern Jewish religious movements, rabbis have generally considered the behavior of a Jew to be the determining factor in whether or not one is considered an adherent of Judaism. Within these movements it is often recognized that it is possible for a Jew to strictly practice Judaism as a faith, while at the same time being an agnostic or atheist. Reconstructionist Judaism does not require any belief in a deity, and certain popular Reform prayer books, such as Gates of Prayer, offer some services without mention of God. Jewish atheists who practice Humanistic Judaism embrace Jewish culture and history, rather than belief in a supernatural god, as the sources of their Jewish identity. One study found that only 48% of self-identified Jews believe in God.
Nineteenth-century and early twentieth-century Reform Judaism in the US, which had become the dominant form of Judaism there by the 1880s, was profoundly shaped by its engagement with high profile sceptics and atheists such as Robert Ingersoll and Felix Adler. These included the writings of rabbis such as Isaac Mayer Wise, Kaufmann Kohler, Emil G. Hirsch, Joseph Krauskopf, Aaron Hahn, and J. Leonard Levy, with the result that a distinctly panentheistic character of US Reform Jewish theology was observable, which many would have viewed as atheistic or espousing atheistic tendencies.
Rabbi Abraham Isaac Kook, first Chief Rabbi of the Jewish community in Palestine, held that atheists were not actually denying God: rather, they were denying one of man's many images of God. Since any man-made image of God can be considered an idol, Kook held that, in practice, one could consider atheists as helping true religion burn away false images of God, thus in the end serving the purpose of true monotheism.
Christianity
High rates of atheism have been found among self-identified Christians in the United States. Out of all Americans who do not believe in God, 5% identified as Catholic while 9% identified as Protestant and other Christian according to the 2007 Pew Religious Landscape survey. Out of all Americans who identify as unaffiliated including atheists and agnostics, 41% were raised Protestant and 28% were raised Catholic according to the 2014 Pew Religious Landscape survey.
There is no single Christian approach toward atheism. The approach taken varies between Christian denominations, and Christian ministers may intelligently distinguish an individual's claims of atheism from other nominal states of personal perspective, such as plain disbelief, an adherence to science, a misunderstanding of the nature of religious belief, or a disdain for organized religion in general.
The Catechism of the Catholic Church makes this explicit. While it 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:
In May 2013, Pope Francis said that atheists may be able to enter Heaven, because the redemptive embrace of Jesus applies to everyone who does good, regardless of their beliefs. The Catechism of the Catholic Church also says Heaven is available to everyone, if they are not Christian and "through no fault of their own, do not know Christ and the Church."