The world of the ascension is a three-part universe with the heavens above, a flat earth centered on Jerusalem in the middle, and the underworld below. Heaven was separated from the earth by the firmament, the visible sky, a solid inverted bowl where God's palace sat on pillars in the celestial sea. Humans looking up from earth saw the floor of heaven, made of clear blue lapis-lazuli (Exodus 24:9-10), as was God's throne (Ezekiel 1:26).
Ascension stories were fairly common around the time of Jesus and the gospel-authors, signifying the deification of a noteworthy person (usually a Roman Emperor), and in Judaism as an indication of divine approval. Another function of heavenly ascent was as a mode of divine revelation reflected in Greco-Roman, early Jewish, and early Christian literary sources, in which particular individuals with prophetic or revelatory gifts are thought to have experienced a heavenly journey during which they learned cosmic and divine secrets. Figures familiar to Jews would have included Enoch (from the Book of Genesis and a popular non-Biblical work called 1 Enoch); the 5th century sage Ezra; Baruch the companion of the prophet Jeremiah (from a work called 2 Baruch, in which Baruch is promised he will ascend to heaven after 40 days); Levi the ancestor of priests; the Teacher of Righteousness from the Qumran community; the prophet Elijah (from 2 Kings); Moses, who was deified on entering heaven; and the children of Job, who according to the Testament of Job ascended heaven following their resurrection from the dead. Non-Jewish readers would have been familiar with the case of the emperor Augustus, whose ascent was witnessed by Senators; Romulus the founder of Rome, who, like Jesus, was taken to heaven in a cloud; the Greek hero Heracles (Hercules); and others.