Is atheism a religion?
Is atheism a religion? The short answer is no, which will be explained in full as you read on.
Why do some people insist that atheism is a religion? The prime reason is that those who make this statement wish to portray atheists as a faith-based belief system, putting atheists on the same playing field as theists. Unfortunately, this makes no logical sense whatsoever.
The term "Atheism" comes literally from the prefix "A" which means "without" and "Theos" which means "god" which gives you "without god". Therefore, all atheists are those who have no belief in God, or rather people who lack a belief in God. Not believing in God does not tell what a person is or thinks, rather the term atheism explains what a person is not. Simply, it says a person does not buy the claims made by theists. Simply not buying something does not mean that you are therefore selling something else.
The claim "atheism is a religion" are usually made by those who use a very loose definition of religion. Usually they use "religion" as a word that could include any group of people with a common belief or way of life. But to accept this is self-refuting. Claiming religion is based on groups of people, everything from baseball teams to people sitting in a waiting room, are now religions. Few would find the argument compelling: "Oranges are made of matter. Stars are made of matter. Therefore, oranges are kinds of stars." Whether something is made of matter is not what distinguishes a star from a non-star.
It is true there are some secular religions (Raelism, Buddhism, Satanism, etc.), but all religions have positive beliefs (not negative or absence of beliefs), rituals, places of worship, religious leaders, and sacred texts. Remember, an atheist is someone who simply lacks a belief in god(s), nothing more and nothing less. Simply being an atheist does not require any ritual performance or participation, nor are there any places of worship an atheist must visit. An atheist is free to accept any view of his/her choice, but whichever they adopt, belief in god(s) is absent.
The above explanation could attract snark remarks such as atheists worship science and praise textbooks and have scientists as religious leaders. Unfortunately, this claim is without any thought or merit. Atheists are known to use critical thinking to distinguish truth from myth (is the Earth flat or not?), and the scientific method is a fabulous objective tool to achieve this. But this cannot be considered religious, because religions demand that you accept certain beliefs without any evidence (often demanding belief despite the evidence clearly pointing the other way). The scientific method only makes claims based on the available evidence, and always remains falsifiable because new discovered evidence could improve, alter, or disprove previous scientific models. This is why people who use the scientific method (rationalists, empiricists, atheists, freethinkers, etc.) tend to be skeptics and not accept everything they told right off the bat - unlike church-goers who unquestionably accept stories like a man could survive inside of a whale for three days.
Atheists, generally being skeptics, are less likely to be religious for the simple fact that religions demand belief without evidence (such as souls or an afterlife). They generally accept naturalistic explanations, because they can be verified, observed, and tested. However, certain religions are very secular that they do not make extraordinary claims, rather they may just be a model to live a certain lifestyle. Choosing a certain lifestyle is not religious in of itself, otherwise we should consider people who eat a lot of meat as religious. Secular religions usually provide a set of ethics and behaviors (such as meditation).
Is secular humanism a religion?
As noted above, atheism explains what a person is not, rather than what a person is. For this reason, atheists usually adopt worldviews that are divorced from belief in god(s). On a large scale, the option atheists adopt is secular humanism.
Theists often say that secular humanism is recognized as a religion by law, and since they wrongly that think atheism is the same thing, then by extension they think even rationalism should be considered a religion; that even anti-religion is religious. But of course they’re wrong again on all counts.
In the 1961 case of Torcaso v. Watkins, Roy Torcaso was denied his commission as notary public when he refused to declare a belief in God. At that time, the state of Maryland’s “Declaration of Rights” required “a declaration of belief in the existence of God” as a qualification for any office of profit or trust in that state. The Supreme Court ruled that such requirements violated Article 6 of the United States’ Constitution, as well the 1st and 14th amendments. But the official ruling also included a series of footnotes, called "obiter dictum," or "said in passing." These are only the personal opinions of the justice, with no official or legal significance. In a dictum footnote attached to his opinion, Justice Hugo Black listed “Secular Humanism” along with “Ethical Culture” and Taoism as religions which do not teach a belief in God. The footnote is not legally binding, which is fortunate since none of those things really count as religion. Imagine attending the church of ethical culture!
So secular humanism is not a religion in any sense, legal or otherwise, and neither is atheism. Religion must include a professed conviction, and simply being un-convinced as to the real-life existence of what they see as mythical characters –hardly counts as that. So atheism alone is no more a religion than health is a disease. One may as well argue over which brand of car pedestrians drive.