There is a strong distinction between Islamic culture and Western culture when it comes to/inregard to understanding the religion, as far as I can see. Westerners (or 'the West') consider the developed modern era as secular, whereas the dark ages are considered religious. Muslims consider their developed era as an age of reason, whereas the dark era is considered to be an age of ignorance--and both are considered as religious. Islamic culture is more religious. However, I’m skeptical about any essential distinctions between modern societies that the serious distinctions are because of the difference in circumstances. Your last sentence seems grammatically ok, but I'm not sure I can understand it. I think the problem is around the word THAT - - more explanation might be needed.

There is a strong distinction between Islamic culture and western culture at understanding the religion, as far as I can see. Westerns consider the developed modern era as secular, whereas the dark era as religious. Muslims consider their developed era as reason age, whereas the dark era as an ignorance age, and both as religious. Islamic culture is more religious. However, I’m skeptic about any essence distinctions between modern societies that the serious distinctions are because of the difference in circumstances.