Atheism is not a religion. Do some, and I mean only some, athiests go at their atheism like some, and I do mean some, believers go at their belief, in a religious fashion? Yes.
What I mean is the constant need to talk about either non belief or belief. The constant need to persuade others in an evangelistic kind of effort. The passionate obsession with being right and to make sure everyone knows it. The intolerance of differing views. Most atheists I have known in my life do not treat their unbelief like a religion. Do some atheists I know treat their unbelief as if it is a religion? Yes. Do most people I know who are part of a religion feel they have to be right and they have to evangelize? No. But unfortunately enough religious people do.
Money can be a god. Material possessions can be a god. An activity like sex or gaming or gambling can be a god. And yes, ironically, atheism can become like a god.