People from different cultures see their religious figures appearing to them in times of disillusionment, fear and/or danger. Buddhists see Buddha, Muslims see Muhammad, Christians see Jesus.
Human live their life by aspiring to other humans. When someone is a deep believer and thinks about their religious figure all the time then it is bound to appear in their dreams or even start appearing in objects. Same thing can happen when we watch a movie late night and some of the action appears in the dream.
The brain lives behind footprints, much like the ones we leave in the sand when we walk down the beach. There are even sights of mass delusions where people convince each other about the presence of something.
A few years back I wanted to test this hypothesis. I devised an experiment. I drew a small dot on a picture above the sky and spread the rumor among UFO believers. In less than 2 hours my photograph became national news and people even started swearing to have seen the light in the street while they were driving and other weird occurrences. Once I planted the seed the thing took off like wild fire.
This is to demonstrate how all religions, beliefs, rumours and conspiracies work. Humans like to trick each other in believing their own version of reality. When too many people gather then the idea gains credibility and nobody questions the original source.