The Apocalyptic literature of Judaism and Christianity embraces a considerable period, from the centuries following the exile down to the close of the middle ages.
(a) The origin of Apocalyptic is to be sought in unfulfilled prophecy.
But later, with the growing claims of the individual and the acknowledgment of these in the religious and intellectual life, both problems, and especially the latter, pressed themselves irresistibly on the notice of religious thinkers, and made it impossible for any conception of the divine rule and righteousness to gain acceptance, which did not render adequate satisfaction to the claims of both problems. To render such satisfaction was the task undertaken by apocalyptic, as well as to vindicate the righteousness of God alike in respect of the individual and of the nation.
Thus, whereas prophecy had to deal with temporary reverses at the hands of some heathen power, apocalyptic arose at a time when Israel had been subject for generations to the sway of one or other of the great worldpowers.
But now as we enter the Greek period (320 B.C. and onwards) there is a gradual change from prophecy to apocalyptic. " It may be asserted in general terms that whereas prophecy foretells a definite future which has its foundation in the present, apoca lyptic directs its anticipations solely and simply to the future, to a new world-period which stands sharply contrasted with the present.