How does religion shape Black Beauty?
There is a verse from the Old Testament which exemplifies a religious precept to which Anna Sewell would most likely adhere.
If you see the donkey of one who hates you lying down under its burden, you shall refrain from leaving him with it; you shall rescue it with him. Exodus 23:5
Though now considered a children's classic and noted for being one of the first in which the animal is the voice of the narrator, the novel Black Beauty, written in 1877, was originally intended for those who worked with horses. Anna Sewell meant for it to be a sort of epistle to those who cared for and used horses, urging them to be kind in their treatment of these animals. She especially wished to effect the end of the use of the bearing rein, a strap that forced a carriage horse's head to remain lifted with the neck arched in a showy fashion. This position often became painful for the horse because it was unnatural and it did not allow the horse to bend his head down, when going uphill with the weight of a carriage and riders, as he normally would, in order to use his back and hindquarter muscles more efficiently. Sewell also wished to draw attention to the mistreatment of workhorses who were forced to carry excessively heavy loads or work long hours. Often, too, such horses were kept in dirty stalls and were underfed when not working. Some owners were abusive to these intelligent animals, as well, thinking of them only as one would an inanimate machine.
It is important to recall when analysing Black Beauty that Anna Sewell gave a statement of intent about why she wrote the story. She did not have bettering the lives of humans through religion in mind. She clearly had the aim of bettering the lives of horses in mind. In a statement, she declared that before she died she wanted to write a story that would "induce kindness, sympathy and an understanding treatment of horses" as the direct aim and goal. This indirectly involves humans as they are generally the ones who are responsible for how horses are treated.
Having said this, the precepts of kindness, sympathy and understanding are precepts embraced by religions, including Christianity, which would be the form of religion dominant in England during the period of the setting around 1870. These precepts are shown most fully in Chapter 36, "The Sunday Club," in which Jerry explains "true" and "real religion" and the one way to "make the world any better":
"If some men are shams and humbugs, that does not make religion untrue. Real religion is the best and truest thing in the world; and the only thing that can make a man really happy, or make the world any better."
These precepts of religion can be seen, then, as the undergirding that shapes the narrative as Sewell builds a story to show humans how to be kinder and truer and more sympathetically understanding so as to "induce kindness, sympathy and an understanding treatment of horses."