The term apocrypha is used with various meanings, including "hidden", "esoteric", "spurious", "of questionable authenticity", ancient Chinese "revealed texts and objects" and "Christian texts that are not canonical".

The word is originally Greek (ἀπόκρυφα) and means "those hidden away". Specifically, ἀπόκρυφα is the neuter plural of ἀπόκρυφος, an adjective related to the verb ἀποκρύπτω [infinitive: ἀποκρύπτειν] (apocriptein), "to hide something away."

The general term is usually applied to the books in the Roman Catholic Bible, and the Eastern Orthodox Bible, but not the Protestant Bible on their claim that it is not God's word. As such, it is misleading in this sense to refer to the Gospel according to the Hebrews or Gnostic writings as apocryphal, because they would not be classified in the same category by orthodox believers: they would be classified as a heretical subset of antilegomenae, to distinguish them from now-canonical ancient antilegomenae such as 2 Peter, 3 John and the Revelation of John, and non-canonical but non-heretical books which were quoted by the Early Fathers such as the pseudepigraphic Epistle of Barnabas, the Didache, or The Shepherd of Hermas. The gnostic writings are generally not accorded any status, not even a negative one: they are ignored, as they are incompatible with the accepted canon prima facie. Non-canonical books are texts of uncertain authenticity, or writings where the work is seriously questioned. Given that different denominations have different beliefs about what constitutes canonical scripture, there are several versions of the apocrypha.

The term historical Jesus refers to scholarly reconstructions of the 1st-century figure Jesus of Nazareth. These reconstructions are based upon historical methods including critical analysis of gospel texts as the primary source for his biography, along with consideration of the historical and cultural context in which he lived.

The historical Jesus is believed to be a Galilean Jew who undertook at least one pilgrimage to Jerusalem, then part of Roman Judaea, during a time of messianic and apocalyptic expectations in late Second Temple Judaism. He was baptized by John the Baptist, whose example he may have followed, and after John was executed, began his own preaching in Galilee for only about two to three years prior to his death. He was an eschatological prophet and an autonomous ethical teacher. He told surprising and original parables, many of them about the coming Kingdom of God. Some scholars credit the apocalyptic declarations of the Gospels to him, while others portray his Kingdom of God as a moral one, and not apocalyptic in nature. He sent his apostles out to heal and to preach the Kingdom of God. Later, he traveled to Jerusalem where he caused a disturbance at the Temple. It was the time of Passover, when political and religious tensions were high in Jerusalem. The Gospels say that the temple guards (believed to be Sadducees) arrested him and turned him over to the Roman governor Pontius Pilate for execution. The movement he had started survived his death and was carried on by his brother James the Just and the apostles who proclaimed the resurrection of Jesus. After splitting with Rabbinic Judaism, it developed into Early Christianity.