A Scanner Darkly + Sharka Todd
Making people feel bad for the doing the "wrong" thing!
To me, a cult is a movement of people where pressure is exerted on individuals to remain within the group and thinking as the group thinks. Individuals are usually welcomed into the cult with open arms but if they attempt to leave, emotional and even physical pressure is brought to bear to discourage them from doing so.
I don't think the beliefs of the group are what makes it a cult. However, cults tend to have authoritarian power structures where members are strongly encouraged to follow the dictates of the leaders of the group and strongly discouraged from thinking and acting independently.
You cannot have a cult that respects the free will of the individual and where the free flow of ideas is allowed. If it did so, it would be a healthy movement with free entry and exit, rather than being a controlling cult.
However, it may not be apparent to new members, or those considering joining, just how controlling the organisation is, and so they may be caught unaware when they realize how much pressure is brought to bear to keep them within the group and thinking as the group thinks.