If my understanding of the occult is correct, rituals (including prayer, singing, cosplay, sacrifice etc) can all give power to an idea. Millions around the world actively believe in Santa and billions more have knowledge of him or participate in santa rituals.

Now, this was all just armchair philosophy. But, I went to the mall, and there really was a santa ! Now, if santa isn't real how did I meet him in such a public place? QED