Apocalipsis 1:18

And I was dead

(κα εγενομην νεκρος). "And I be came dead" (aorist middle participle of γινομα as in Apocalipsis 1:9; Apocalipsis 1:10, definite reference to the Cross).I am alive

(ζων ειμ). Periphrastic present active indicative, "I am living," as the words ο ζων just used mean.Forevermore

(εις τους αιωνας των αιωνων). "Unto the ages of the ages," a stronger expression of eternity even than in Apocalipsis 1:6.The keys

(τας κλεις). One of the forms for the accusative plural along with κλειδας, the usual one (Mateo 16:19).Of death and of Hades

(του θανατου κα του αιδου). Conceived as in Mateo 16:18 as a prison house or walled city. The keys are the symbol of authority, as we speak of honouring one by giving him the keys of the city. Hades here means the unseen world to which death is the portal. Jesus has the keys because of his victory over death.

See this same graphic picture in Apocalipsis 6:8; Apocalipsis 20:13. For the key of David see Apocalipsis 3:7, for the key of the abyss see Apocalipsis 9:1; Apocalipsis 20:1.