Answer:
Because the ideas about hell described by Dante were based on the biblical text, which is the main source of Christian knowledge.
Explanation:
Dante was more inspired by Greco-Roman myths to describe hell in his narrative, than biblical texts. For this reason, many believe that "Dante's hell" is not necessarily a reflection on Christianity, but rather on the way the civilization of the Middle Ages thought about sin and the way this thought was influenced by the Greeks and Romans.
Biblical hell, for example, is not divided into circles, is not composed of flames and does not stay underground as Dante presents it, but the medieval imaginary and Greco-Roman legends approach hell in this way.
