Myth:
Everyone has a religion and everyone worships something. Atheists worship the human race and their own human intellect. This leads many to become communists who worship the government.
Response:
The idea that atheists worship themselves in any manner like religious theists worship their god is absurd enough to dispense with quickly. Perhaps because of this some religious theists think it is easier to claim that atheists worship something similar, but larger: all of humanity, the human intellect, or perhaps human government. If everyone has a religion and everyone worships something, then these must seem like plausible candidates. This is just a myth, though, and is not true.
Worship is normally defined in a number of ways: "reverent honor and homage paid to God or a sacred personage, or to any object regarded as sacred; adoring reverence or regard; to render religious reverence and homage to; to feel an adoring reverence or regard." Is any of this true about how any atheists feel towards humanity, human intellect, or governments? Do any atheists pay "reverent honor or homage" to humanity in general? Do any atheists regard the human intellect as "sacred" or render to it "religious reverence and homage"? Do any atheists feel "adoring reverence or regard" for any government?
Given the diversity of human belief and action, it's plausible that there could be a couple of atheists here or there who actually do such things. I've never met any atheists like this, though, and those I have known would not only regard such attitudes as bizarre, but might even wonder if they were signs of mental illness. None of this even comes close to describing how atheists generally behave nor does it describe anything that necessarily follows from atheism itself.
If we focus on the actual practice of "worship," the sorts of things which religious theists do when they actively worship their gods, we find that there is even less of a reason for saying that atheists worship humanity, human intellect, or governments. Atheists do not pray to any governments. Atheists do not hold religious services in honor of the human intellect. Atheists do not erect monuments to the human intellect as a means for glorifying and exalting it over everything else. What objects might be described as "monuments" to human intellect are erected and shared by atheists and theists, indicating that it's not an example of religious belief or worship.
If we think of "worship" as a means for exalting something above everything else, we'd have to admit that some atheists may arguably do this with humanity, the human intellect, or with government but not at rates that appear to be any higher than theists. Some misunderstanding might occur because Humanism, a philosophy adopted by many atheists, could appear to be a belief system that exalts humanity. That isn't true, however; humanism is a philosophy that places human needs and concerns at the center of attention, it doesn't "exalt" or "glorify" humanity in any way, much less make it an object of worship.
The idea that atheists worship government is commonly attached to the claim that atheists tend towards communism or are all communists. It is argued that since atheists worship humanity, and since human government is the highest human institution, then atheists must worship government. Communism is a system with a totalitarian, absolutist government that rules over everyone's lives, and this must be the natural form of government for people who worship the government. It all fits together, if you're willing to accept unsupported claims as if they were unquestionably true.
People who repeat the above myth as if it were fact rarely, if ever, offer actual evidence to back it up. They cite no statistical or sociological data that would show that their claim has any truth to it. They don't even really offer any arguments on behalf of their claim, though there is one implicit in the statement: it is concluded that atheists must worship something because of the premise that everyone worships something. This premise is not obviously true and is, in fact, arguably false. Unless it can be well supported, then the conclusion certainly cannot be accepted as anything but speculation (at best).
If anything, it might be argued that theists are the ones who worship humanity. The gods people believe in always look suspiciously like the believers in attitudes, desires, and agendas. There's a good argument to be made for the idea that rather than humans being created in the image of some god, all gods have been created in the image of human believers. This would make gods little more than abstractions of human ideals and desires which, in turn, means that people who worship these gods are in fact worshipping abstractions of their own ideals for themselves, for humanity, and for human governance.

