Don't feel the need.
As an atheist, I am not part of a club or organization that I need to identify with. My atheism is only a response to a single claim, that a god exists.
I also don't believe in Bigfoot or the Loch Ness monster, and don't feel the need to wear clothing identifying me as disbelievers in those.
I might consider wearing Secular Humanist clothing, or Skeptic clothing, but I don't presently do that either.
As an atheist, I am not part of a club or organization that I need to identify with. My atheism is only a response to a single claim, that a god exists.
I also don't believe in Bigfoot or the Loch Ness monster, and don't feel the need to wear clothing identifying me as disbelievers in those.
I might consider wearing Secular Humanist clothing, or Skeptic clothing, but I don't presently do that either.
You'd believe if you just opened your heart" is a terrible argument for religion. It's basically saying, "If you bias yourself enough, you can convince yourself that this is true." If religion were true, people wouldn't need faith to believe it -- it would be supported by good evidence.