This dissertation examines temporal frames in the Gospel of John and the Johannine letters and traces the ways that these texts and those who received them constructed and employed temporality to shape belief in Christ. Building on existing scholarship on Johannine literature and temporality, I situate these writers and their readers within their contemporary Greek, Roman, and Jewish social and rhetorical contexts, exploring the use of temporal markers, calendrical calculations, and claims about the past, present, and future in ancient discourses of self-definition. The Gospel of John uses an account of Jesus’s life and deeds to assert the God of Israel’s exclusive prerogative to create, control, and dominate not only time but also earthly authorities. The writer(s) of the Gospel place the Logos “in the beginning,” situate events within Jewish temporal frames, and align Jesus’s resurrection with solar time to portray Jesus as a sovereign, divine agent. The Johannine letters also employ temporality, but differently. The letters link the past with the present to establish an identity for the audience by assuring them of their genealogical and temporal bonds with Jesus. The letters seek to distance perceived opponents, who are labeled “Antichrist,” by describing them as agents of the devil who sinned “from the beginning.” A later group of Christ believers known as the “Quartodecimans” received and adopted Johannine temporality for their own purposes. Celebrating Easter in full coordination with the Passover, for example, Melito of Sardis envisioned God’s salvific work in a continuity that directly linked salvation from the Exodus to Jesus’s death and resurrection. Melito employed temporality to create a mobile and porous boundary between Christ believers and other groups and to claim the theological superiority of his own group. This analysis of Johannine literature indicates that ancient writers widely employed claims about temporality to distinguish their perceived audiences from other groups. These writers sought to persuade the followers of Christ to adopt particular temporal outlooks and to ascribe them to concomitant theological assertions. They thus established their exclusive authority to interpret Jesus’s life and deeds and defame false teachings.