Revelation 1:17
The context
John, exiled on Patmos, sees a vision of the risen Christ among seven lampstands and falls as though dead. The figure lays a hand on him and speaks the reassurance formula used by God in Isaiah, then identifies himself as the living one who died and now lives.
What it establishes
It establishes the self-identification of the speaker in the vision and the reassurance that accompanies it: the one who addresses John claims the first and last, and speaks as one who has passed through death.
What it does not establish
It is not a timeline. The verse is a self-identification, not a chronology of the visions that follow, and it gives no dates. Nor does the title by itself settle how the book's imagery maps onto later events, which the text does not supply a key for.
Short note, first pass, October 2026. Corrections welcome.
Cited in these answers
Part of Scripture, Opened — the exegetical layer behind every citation on this site. Scripture quotations are from the ESV.