The Cult Strikes Me As A Metaphor For An Insect Colony

The hierarchy, specialization, rituals, keening, special food & drink & drug, the inexorability of fulfilling predetermined functions, including bringing in fresh material from the outside into the hive, culling the aged, clearing out the detritus with purifying fire.

You may have noticed that all the members had a certain lack of, well, humanity.

It's a wonderfully thought-provoking film. I do also think its a bit of a slight dig at German/Nordic proclivity to order, a certain coldness.