Apocalyptic literature is a genre of prophetical writing that developed in post-Exilic Jewish culture and was popular among millennialist early Christians. Apocalypse is a Greek word meaning "revelation", "an unveiling or unfolding of things not previously known and which could not be known apart from the unveiling".

Early Christianity, otherwise called the Early Church or Paleo-Christianity, describes the historical era of the Christian religion up to the First Council of Nicaea in 325. Christianity spread from the Levant, across the Roman Empire, and beyond. Originally, this progression was closely connected to already established Jewish centers in the Holy Land and the Jewish diaspora throughout the Eastern Mediterranean. The first followers of Christianity were Jews who had converted to the faith, i.e. Jewish Christians. Early Christianity contains the Apostolic Age and is followed by, and substantially overlaps with, the Patristic era.