What motivates such stubborn beliefs

There are two reasons:

1) we cling to beliefs that resonate with our sense of "self".

2) we cling to beliefs that resonate with our social groups.

One of the reasons was the cult member's personality resonated with the personality of the Seekers. And the second reason being the ...

It is easy when our trust is broken. We see the truth from a bird-view, but when our idea resonates with the group, it becomes much harder to break the chain of beliefs and see the reality.

This is because our group gives us a sense of belonging.

This idea is taken from the book 'The...

Seekers were a group of people in the 1950s who were believed to have been warned by the aliens that a massive flood would swap the western seaboard of the U.S. on December 21, 1954. They published this prophecy in the local newspaper. And Festinger wanted to inspect what this cult actually was, ...

The prophecy turned out to be a huge failure. Nothing happened to the western coast that day.

To this, the members of the cult should have abandoned the cult, right?

This question arises for sure.

This is because when their beliefs were put to an extreme end, the Seekers went through a mental phase called Cognitive Dissonance. This put them in a grave situation and to reduce this discomfort, they could respond in one of two ways: whether they have to ac...