BibTeX:
@incollection{Various,
  author = {Various},
  title = {Sacred Moments with Grandpa},
  booktitle = {Baha'i Stories for Children},
  url = {https://bahaistoriesforchildren.blogspot.com/2016/09/sacred-moments-with-grandpa.html},
}

APA:
Various. Sacred Moments with Grandpa. In *Baha'i Stories for Children*.

MLA:
Various. "Sacred Moments with Grandpa." *Baha'i Stories for Children*, n.d..

Chicago:
Various. "Sacred Moments with Grandpa." In *Baha'i Stories for Children*, n.d..