As an aside, remember that in RuneQuest we have initiates and lay members. Initiates are those who have experienced the cult’s magical secrets. They are able to act as conduits for the deity and wield its Rune magic. That is a deep connection, like being married or the member of a family – it is not something that is done casually.Casual members are lay members – those are the folk that show up to the worship ceremonies and feasts, learn some spirit magic and skills from the cult, but might have a deeper tie with another cult.
Associate members are initiates of one cult who can participate in the magical secrets of another, closely connected cult. They might even have special roles in that closely connected cult. As a result they have a deeper magical connection with the other cult than mere lay members, even though technically they are not actually members of that cult. A good example would be the tie between Issaries, Chalana Arroy, Lhankor Mhy and Orlanth, or between Orlanth and Ernalda.
In some communities most members of a cult are initiates or associate members – think like the members of the Orlanth cult in an Orlanthi clan or the Pavis cult in the Real City. In other communities, most members of a cult are lay members – think the Pavis cult in New Pavis or Pavis County.
A general rule of thumb is that most adults are initiated into a cult. That’s a very fuzzy rule admittedly, but generally true.
Now mechanically, that may not be the most useful way of presenting a NPC (and many initiates probably don’t actually have more than a single Rune Point).