BibTeX:
@incollection{Various,
  author = {Various},
  title = {On one occasion the Master illustrated that prayer can be selfish},
  booktitle = {bahaistories.com archive},
  url = {https://bahaistories.com/subject/prayer},
}

APA:
Various. On one occasion the Master illustrated that prayer can be selfish. In *bahaistories.com archive*.

MLA:
Various. "On one occasion the Master illustrated that prayer can be selfish." *bahaistories.com archive*, n.d..

Chicago:
Various. "On one occasion the Master illustrated that prayer can be selfish." In *bahaistories.com archive*, n.d..