In order to answer the question of whether or not the three hermits in Tolstoy's "The Three Hermits" are supernatural beings, it is necessary to do a textual analysis: look to and examine the words in the text to determine if Tolstoy has provided any indicators of the answer. One such indicator would lie in the sailor's description of the hermits. Another would lie in the Bishop's encounter with the hermits. A third indicator would lie in the final events of the story, which Tolstoy attributes to "An old legend current in the Volga District."
The first indicator, the sailor's description, gives a very physical account of the three old men who are hermits living "for the salvation of their souls." Firstly, they live in an earthen hut; have food and water to drink, which they share with the sailor relaying his experience; they are strong and able and help him mend his boat. Secondly, the eldest and smallest, who has a bent back, wears a priest's cassock and has such an ancient beard that it is discoloring. The strongest wears a peasant's coat and has a broad yellowish beard and needed no help turning the sailor's boat over. The stern one has a snow white beard hanging to his knees and wears only a loin covering made of matting from leaves. These are very concrete, very human qualities; the discoloring beards may even suggest mineral deficiencies. There is nothing that Tolstoy has provided in the sailor's description to suggest these are supernatural beings.
The second indicator is the Bishop's encounter with the hermits. Aside from confirming the sailor's description of the three men, the Bishop's encounter offers no new descriptive information except to say that the hermits bowed low and lower to the Bishop indicating that they are well versed in the ways of Russian society and must have lived long within it before secluding themselves. Otherwise, the Bishop's sole attention is set on teaching them to "pray aright," which suggests that the Bishop's impression of them is that they are not spiritual men, which is a status that pretty much excludes being supernatural beings. So far, Tolstoy has given no information to suggest he is developing in the reader a perception of these hermits being anything other than human beings.
The third indicator comes at the end of the story when the hermits, having forgotten the Bishop's ritualized lessons, come hurrying across the water to beg the Bishop to teach them again. This certainly might--and does--raise the question and possibility of the hermits being supernatural beings, since it is rather uncommon for humans to walk on water ... . But before deciding that Tolstoy has been misrepresenting the hermits thus far, examine the Bishop's reaction, which is significant for what he does and what he does not do.
Firstly, the Bishop does recognize their holiness and superiority to him: He enjoins them to leave what he taught them forgotten and to pray "for us sinners." Grammatically, the use of "us" means that the Bishop is absolutely including himself. What he does not do is react to the hermits as to supernatural beings. He absolutely reacts to them as human beings, as made of the same stuff as himself. His humility before them stems from the realization that, being men like himself, they have a pure spirituality. And this is Tolstoy's point: Spirituality in human beings derives from within, not from without through empty ritual.