The historicity of Jesus' baptism by John is virtually certain. The historicity of the theophany (the Spirit's descent and divine voice) is probable, but its timing as contemporaneous with the baptism is open to question. As a prophetic call-vision, the theophany quite possibly happened at a later time. Based on an exploration of John's baptism and ministry within the context of Second-Temple Judaism, the significance of Jesus' baptism is explored: it is a significant turning point in Jesus' life; Jesus is identifying with Israel's need to repent, and he is in agreement with John's vision for a reconstituted Israel; since Jesus is a disciple of John, the beginning of his ministry involves baptizing within John's movement. It is also important to understand Jesus' later ministry along a trajectory that begins with Jesus' association with John. This later ministry shows both continuity with and development beyond Jesus' early involvement with John.