With the death of one pope and the election of a new one, I keep hearing the phrase "over a billion Catholics worldwide." This seemed a tad large to me. I've often wondered at the sources for different denominations claims for their member numbers. I've always assumed that it was a self-reported statistic, that the central bureaucracy of these denominations supplied the stats. This made them suspect in my mind and of doubtful accuracy. Of course a religion is going to claim the largest numbers they can get away with. This makes them more influential and substantial.

"Oh, a religion would never fudge such numbers! How can you even think that? You're accusing the leaders of lying! You nasty, nasty man!"

Mainly it comes down to how you define a "member" of a religion. Me, I think somewhat regular attendance might be a requirement. Heck, once every year or two would be fine in my book. The Catholic Church has an interesting method: baptism. That's it. If you were baptized, you're Catholic till you die by the Church's reckoning. So, apparently, I'm counted as Catholic although I haven't attended a service in 35 years and have a non-Christian spiritual practice. I believe some things that might make a Catholic priest blanch from their heretical nature. Yet I'm counted as Catholic? How... odd.