1. Atheism is a religion
This mixes well with #2 but is also the most popular argument against atheists. When atheists, particularly anti-theists (those who vocally oppose religion) speak out against religion, they are accused of being religious. Ignoring the fact that calling something religious as an insult, while defending religion is beyond ironic, it simply is not true, as atheism lacks the tenets to be a religion.
The Merriam-Webster Dictionary defines religion as, “the belief in a god or in a group of gods,” or, “an organized system of beliefs, ceremonies, and rules used to worship a god or a group of gods.”
Atheism lacks all of the above. Atheists don’t believe in god(s) so there is no worship, but there is no organized set of things atheists must believe in, no ceremonies and no rules.
It’s also worth noting that not believing in something does not make something a religion. Is it a religion to not believe in unicorns? This would be like saying, “my favorite sport is not playing baseball, and my favorite television station is ‘off’.”
(Image: David Shankbone / Wiki Commons / Creative Commons)