BibTeX:
@incollection{Various,
  author = {Various},
  title = {In 1914 the Master wrote to the friends in Denver concerning how to convey the…},
  booktitle = {bahaistories.com archive},
  url = {https://bahaistories.com/subject/teaching},
}

APA:
Various. In 1914 the Master wrote to the friends in Denver concerning how to convey the…. In *bahaistories.com archive*.

MLA:
Various. "In 1914 the Master wrote to the friends in Denver concerning how to convey the…." *bahaistories.com archive*, n.d..

Chicago:
Various. "In 1914 the Master wrote to the friends in Denver concerning how to convey the…." In *bahaistories.com archive*, n.d..