If there's a correlation between the religiousness of a commune and the longevity of it, I'd guess that it's due to the fact that it's harder to maintain cohesi

If there's a correlation between the religiousness of a commune and the longevity of it, I'd guess that it's due to the fact that it's harder to maintain cohesion with openly expressed dissent and doubt, and religious-based groups have an additional tool to combat that compared to secular ones (i.e. invoking divine fiat).