Eliyau was always an angel according to Kabbala

 Ency Judaica According to *Moses b. Shem Tov de Leon, Elijah belongs to the angels who advocated the creation of man (Cordovero, Pardes Rimmonim, 24:14); accordingly, Elijah is an angel who dwelt only temporarily on earth as a human being, before again ascending to heaven. Moses *Cordovero compares Elijah's life with the fate of Enoch (ibid., 24:13), as the two are the only biblical personages who were carried off from earthly life in an extraordinary manner. The further fate of Elijah and Enoch in heaven is imaginatively described by Jewish mystics. While Enoch's body is consumed by fire and he himself is changed into *Metatron , the highest angel, Elijah remains after his ascension in possession of his earthly shape, which is why he can maintain his association with the human world and, when necessary, reappear on earth. Though his body is not made from dust like that of human beings but came from the tree of life, it enables him to carry out God's commands and miracles (ibid.; Zohar, 1:29a; 2:197a; Yalk. R. 27). Therefore, unlike Enoch who is known only as the archangel Metatron, Elijah keeps his name under which he intervenes in the fate of the Jewish people. The *Zohar , like the Talmud, tells of devout men to whom Elijah is supposed to have revealed himself. In the later mystic literature, Elijah's comments on the secrets of the Torah are extremely frequent. Elijah prophesied the births of Isaac *Luria and *Israel b. Eliezer Baal Shem Tov to their parents. He appeared frequently to Israel Baal Shem Tov, and also played an important part in the legends of the ẓaddikim.