The Luonnotar are a group who denies that the gods are gods at all. To many this is beyond blasphemy, it is idiotic.
But blasphemy is enough for The Order, and they rounded up those they could find (the Luonnotar kept their membership secret). They were chained in the city plaza and told to repent for their blasphemy, to repent of their claims that the gods weren't real gods. The Luonnotar refused so the Order Prior called down a pillar of fire to destroy them. The pillar scorched the stone of the plaza, burnt off the chains but left the Luonnotar unhurt.
The reason they weren't hurt was because Junil was unwilling to harm those that were actually correct. The gods in general are confused about the Luonnotar, and worry that their knowledge might be evidence that the One has returned to tell them the truth (since the gods didn't tell them this). The gods have, thus far, refused to act against the Luonnotar.
http://fallfromheaven.wikia.com/wiki/Luonnotar