I cannot stand the statement "atheism is a religion". Atheism is not an assertion nor a belief. It is the rejection of theistic claims about a god or gods. That's it. Nothing more than that. It's not true or correct to say atheism is a religion and the statement is often used to equate religion and atheism as two things on the same playing field. But let's grant the statement that "atheism is a religion" and see what that means. First, we need to decide how atheism is like a religion. Do we have a uniform set of beliefs? No. Do we have rituals? No. Do we have one particular book or a set of books in which all of our ideas are placed? No. Do we have some standard of morality that we demand others must follow? No. Do we advertise? Yes. Some atheist organizations advertise on the side of buses and billboards as do some churches. Do we cast people out of atheism? Even the question is absurd given that atheism is an expressed doubt about theistic claims. Do we have a ton of instances where an atheist has killed in the name of atheism? No. We have a number of cases where someone has killed others in the name of a religion. That does not necessarily mean the religion is bad, but it is certainly used as a motivation to commit violent acts against others. Bad people do bad things because they want to do them and the same can be said for good people. If the religion is used as a motivation to do good or bad things, then I think the religion ought to be subjected to scrutiny and skepticism. Do we tell others how to dress because of atheism? No. Do most atheists attempt to restrict your rights in public policy, which affects us all because of atheism? No. This is an absurd question too, given what atheism actually is. So we advertise. Some of us evangelize. I'm an advocate of evangelizing. You need to get your message out there and make yourself be heard and speak to issues that affect us all in the communities in which we live. You need to say, publicly, that you exist. There is great power in just showing people who you are.
The people that claim "atheism is a religion" are those that see atheism as a threat to their tightly held religious/spiritual beliefs and it's a response to outspoken atheists. I've seen this claim from a number of religious and spiritual people that would like for us atheists to shut up and sit down with our critiques of their beliefs. They have not learned the distinction that can be made between them as persons and the beliefs they hold. You can still be the person you are with a different set of beliefs or no beliefs at all. I or any other atheist can maintain respect for a theist as an individual and criticize their beliefs. I can respect YOUR RIGHT to hold a particular belief and not the belief itself. This is something that a lot of theists do not seem to understand. I as an atheist grant you respect because of our shared humanity but if you bring illogical, unsupported, supernatural claims to me, expect me to take those beliefs to task. Persons are worthy of respect tentatively, but that is not true of their beliefs. I do not care how nice you are or how charitable you may be, your beliefs will not get 'respected' until you demonstrate why they ought to be respected. A lot of theists that I have encountered view 'respect' as acceptance and accommodation of their claims without critical inquiry or push back when their claims have stepped into places where they have no business. Refusal to agree to those terms leads to unwarranted comments about not respecting them as persons, closed-mindedness, "fundie atheism" and all sorts of strange name-calling. Demanding respect for your beliefs from the jump is an automatic sign that you will assert something that you do not intend to work for and I will not accept that demand. The demand is unnecessary. Express your beliefs but do not demand nor expect respect for them until you earn it.
Name calling: If I call you an idiot within the discussion or call your beliefs illogical or stupid, it's within the context of the discussion we are having. I have been shown to be an idiot and many times by my own girlfriend. It happens. Put your ego aside. Some discussions do get nasty. Some people are total assholes regardless of their belief or non-belief.
Arguing from the idea that atheism has the potentiality as being as bad as religion is a pathetic argument because it's a cheap shot at atheism without looking at reality. Call me when an atheist because of atheism crashes a plane into a building or chops off their daughters head because she is in violation of some atheist tenant(which do not exist no matter how many theists claim they do). Call me when atheists are insisting a woman does not have the right to choose because she is in violation of another atheist tenant. This potentiality argument screams of weakness and "I do not have any other viable arguments". It's flailing around for the sake of flailing around. Stop claiming that we are doing the same kinds of things when you do not have evidence to back up the claims you are making.
There is also this problem some religious and spiritual people have with atheists that are outspoken and do not hide the fact that they are atheists and express it freely. Some of us wear t-shirts, blog, say it on Facebook or Twitter. We are not telling the religious/spiritual people to shut up, but they certainly want us to be silent and be okay with that and then they turn around and express they are advocates of free speech. In other words they are advocates of free speech and expression until such an expression hits too close to home. Religious/spiritual folks can express their beliefs as much as they want. If someone tried to prevent them from speaking, I would be against that. However I will not nor will I encourage others to be silent or soft with their criticism of religious/spiritual beliefs.
Atheism is NOT a religion. It is not asserting or claiming anything. No positive assertions at all. Atheism does not tell you how to lead your life or how to treat others but that is not a reason to dismiss atheism as a tenable position. If a theist has a problem with a particular atheist, then they have a problem with that atheist and should not use that as a way to attack ALL atheists or atheism. It's like being mad at one woman who claims to be a feminist and using that grievance as an attack on ALL feminists and feminism. It's wrong.
We atheists are not going anywhere and neither are the religious/spiritual folks. We are not going to shut up and you will not shut us up. We will speak on issues of justice, public policy, women's issues, politics, law, medicine, business, sports, technology, etc. Get use to us because we are not going anywhere.