BibTeX:
@incollection{Various,
  author = {Various},
  title = {How the second “Letter of the Living” recognized the Báb},
  booktitle = {Baha'i Stories Blog},
  url = {https://bahaistories.blogspot.com/2016/08/how-second-letter-of-living-recognized.html},
}

APA:
Various. How the second “Letter of the Living” recognized the Báb. In *Baha'i Stories Blog*.

MLA:
Various. "How the second “Letter of the Living” recognized the Báb." *Baha'i Stories Blog*, n.d..

Chicago:
Various. "How the second “Letter of the Living” recognized the Báb." In *Baha'i Stories Blog*, n.d..