#religiousness

However, I checked Google ngram,

and fascinatingly discovered this. Middlemarch was published in 1871 (same year Alice bands were invented. Fun fact that I know for some reason) so it makes sense that she used "religiousness".

I haven't done any research (😔) and am purely hypothesising here, but I'm presuming that prior to the 19th century, atheists (or nullifidians I suppose) were so few and far between in the English-speaking world that a term for how religious one was wasn't necessary, so piety and zeal fulfilled its roles.

As for why religiousness came before religiosity? Maybe "-ness" as a default dates back that far, but after it took off, some people began to 'correct' it to a word that fit better, and when that word became popular, it quickly replaced the clunkier version.

“If a man is married with a righteous wife, he will live a harmonious life even if he is poor.”