There is one inherent Absurdity of believing in one, and only one, Religion.

If there is one true religion, then the rest are false.

Any religion that is not your religion is not-religion because it is not your one true religion.

Ergo, all other not-religions are heresy.


Therefore, the odds are your religion is heresy since it is outnumbered by many others.

The set of all not-religions is the set including all not-your religions and your religion.  So Christianity is included in the set not-Buddhism. The negation of your religions is the rest of the Venn diagram.  

But how does any one find out which is true?