This also goes for people today. E.g. terrorist. They believe the shit they talk about.
“What I think this show has fallen into is the assumption – almost always made by someone outside a society looking in – that the local religion is so silly that no one of true intelligence (which always seems to mean ‘the ruling class’ – I am amazed how even blue-collar students will swiftly self-identify with knights and nobles over commoners when reading history) could believe it. This is the mistake my students make – they don’t believe medieval Catholicism or Roman paganism, and so they weakly assume that no one (or at least, none of the ‘really smart’ people) at the time really did either. Of course this is wrong: People in the past believed their own religion.”