No matter what you truly have faith in, your clothing doesn't have to reflect that. Christianity, Buddhism, Agnosticism; it doesn't matter because the symbols are really what counts. Upside-down crosses, Roman gladiators-turned-gods and elephants with a bunch of arms look fucking siiiiick on your T-shirts, bruh. It would be sacriligeous NOT to take advantage, right?
Rely on religious iconography. The more conflicting ideologies, the better.