why do athiests proselytize, page-87

Religion must have been the bee's knees when everyone in your area believed the same thing - like being in a club with an invisible president who could do whatever you wanted as long as you were in his favour and asked nicely.

Imagine the embarrassment when communications and transportation rapidly developed and put each group in contact with each-other - clearly evident that each group believed in exactly the same way, but in different and incompatible gods/spirits/creators.

A few tried, and a few still try, to say that they are all faces of the same god, but everyone knows that's a cop out and the other religions aren't buying being a "face" of something else, so each group or religion must decide whether they recognise that all are fabricated, or whether they retreat to the common position of "we're right, and all the others are wrong".

Of course, that's what's happening. The Churches have all retreated to the position of "We're right - they're all wrong.", and in secular nations where there are no significant penalties for being a non-believer, per capita numbers of religious believers, and interactions between believers and the Church, are falling.

The other hurdle is the dramatic changes over time within religions. It's one thing to laugh at the beliefs of other religions, but with the excellent work of historians now available to all we can get a good look at how religious belief has changed over time and it's altogether more difficult for a believer to laugh at the version of their religion as it was practiced 100/200/500 years ago than it is to have a good chuckle over Thor and his big hammer.