Archaic KJV Word
Presently
Modern equivalent: immediately
What Was Lost
The instantaneous divine power. The Father would presently give twelve legions of angels -- not 'eventually' or 'soon' but this very instant, before the sentence ended. The fig tree presently withered -- immediately, visibly, now. The weakening of presently from 'now' to 'soon' drains the miracles of their shock.
Closest Survivor in Modern English
present (the adjective 'present' still means 'here now' -- the same immediacy the adverb lost)
Peak Usage (1611)
KJV Matthew 26:53 -- 'He shall presently give me more than twelve legions of angels'; Matthew 21:19 -- 'And presently the fig tree withered away'
Died ~1800
Shifted from 'immediately/at once/this very instant' to 'soon/shortly/in a little while,' weakening urgency to vagueness.
What Replaced It
“immediately”
Clinical; presently-as-immediately carried dramatic urgency -- right now, this instant
“at once”
Emphatic but less vivid; presently had the force of 'before your eyes'
“soon”
The modern weakened meaning -- 'at some unspecified near future time'