Leon Festinger infiltrated the Seekers with the goal of studying their cognitions and reactions when their beliefs failed, hence the name of his book When Prophecy Fails. He focused on them primarily to study a thought-process known as cognitive dissonance. Festinger and his colleagues essentially wanted to study cult members reactions and coping mechanisms when the UFO did not come to get them on December 21st, 1954. When the UFO didn't come, a majority of the members became convinced that the UFO would come on Christmas Eve. It was the second time around that the members experienced the greatest amount of dissonance. In the book, Festinger and his colleagues write "The experiences of this observer well characterize the state of affairs following the Christmas caroling episode—a persistent, frustrating search for orders."[6] After this incident, many of the members returned home and abandoned their initial belief. Those who did not claimed that their group's belief and faith had saved the rest of the world from the disaster the aliens had warned them of.
Or was you hinting us to this The Brotherhood of the Seven Rays aka the seekers
Leon Festinger infiltrated the Seekers with the goal of studying their cognitions and reactions when their beliefs failed, hence the name of his book When Prophecy Fails. He focused on them primarily to study a thought-process known as cognitive dissonance. Festinger and his colleagues essentially wanted to study cult members reactions and coping mechanisms when the UFO did not come to get them on December 21st, 1954. When the UFO didn't come, a majority of the members became convinced that the UFO would come on Christmas Eve. It was the second time around that the members experienced the greatest amount of dissonance. In the book, Festinger and his colleagues write "The experiences of this observer well characterize the state of affairs following the Christmas caroling episode—a persistent, frustrating search for orders."[6] After this incident, many of the members returned home and abandoned their initial belief. Those who did not claimed that their group's belief and faith had saved the rest of the world from the disaster the aliens had warned them of.
https://en.m.wikipedia.org/wiki/The_Seekers_(rapturists)
that's the one. thanks