In Buddhism the two beings that are often confused with the Christian concept of the devil, Yama and Mara, are also Bodhisattvas. Lord Yama’s job is to make sure beings receive the appropriate karmic retribution in the appropriate hell realm. The hell realms as described in Buddhism are not so different from those visualized by Dante in The Inferno. Lord Yama is the Bodhisattva assigned by the Buddhas to rule the ghosts and hell realms, but he must not be thought of as the King of the Ghosts, because he is a Bodhisattva and ghosts are ordinary beings. He resides in the Suyama Heaven, the third heaven of the Desire World. He is also considered a dharma protector and as one of the “Eight Guardians of the Law.” This is why Lord Yama is often shown holding the “wheel of life” with its six realms of existence and the twelve links of dependent origination.
Mara, the tempter who is also called the Evil One, has the job of testing living beings to make sure they are progressing on the path. He and his demon followers are emanations of Buddhas and Bodhisattvas who test those engaged in self-cultivation. He appears in the texts both as a real being (i.e. as a deity who is the King of Demons of the Paranirmita Heaven, the sixth and highest heaven in the desire realm) and as a symbol of everything that hinders the arising of wholesome roots and progress on the path of enlightenment. This includes the internal difficulties encountered by the practitioner. There are four kinds known as the Four Maras: 1) skandha-mara or incorrect view of self; 2) klesha-mara or being overpowered by negative emotions; 3) matyu-mara or death that interrupts the spiritual practice; and 4) devaputra-mara or becoming stuck in the bliss that comes from meditation.
Seeing these fearsome beings as bodhisattvas who are really responsible for helping us on our evolutionary path puts the so called “devil” in a very different light.