I think what you're saying is absolutely true, and a better example would be culture in general. There's a certain continuity in the cultural practices of a people in a certain region, with religion being one of the most resilient... but also other things like food, music and, of course, language.
However, all of those change over time. It's funny for me that the Americans of today would almost certainly consider the Americans of the 1950's a bunch of racists and homophobes. A culture can change over time so much as to be more different in 75 years than when actually compared with that of other countries. The continuity exists but change can be very fast. Look at the culture of any European "country" and you'll see just how much change happens. An extreme example, perhaps: the Swedes of the year 1000 compared with the Swedes of 2000. The people inhabiting what we call Sweden today were Vikings back then. I don't believe they had a concept of Sweden yet, as a country, though the regions around Stockholm (which didn't exist yet) and Uppsala (a small region which later grew far North and South to form Sweden proper) seem to have already had a sort of cultural identity (see https://en.wikipedia.org/wiki/Varangians). These people were raiders and conquerors - they may have founded the Kievan Rus state and served as elite guards in the Byzantine Empire, which shows just how much of a bad ass warriors they were. How does present-day liberal, tolerant and egalitarian Swedes relate to their ancestors? If they could meet today, the modern fella would lose their head in no time, literally.
