Our whole-ass society is structured around Christian norms. Holidays, liquor laws, businesses closing on Sunday, loads of idioms and turns-of-phrase, it is pervasive and so normalized that any deviance is seen as shocking. (At least we aren’t one of the countries where heresy is still an actual crime)
We keep living next to rivers because reliable water is the single most important consideration. Flooding happens. Most parts of the world independently developed sun and moon worship as well, and name colors in roughly the same order.