The theological problems posed by eschatology are numerous and complex. Adequate answers must take into account at least four considerations. First, the gospel prophecies were never intended to be understood with unimaginative literalness. Just as it is misguided to mine Genesis for scientific data about the physical universe, so too is it wrong to turn the similes and metaphors of NT eschatology into information about future cosmological states.
Salvation-history is not a pre-determined scheme so much as it is a dynamic relationship between God and his people. The Lord can shorten the interim period (Mk 13-20) or lengthen it. (Luke 13:6-9) His Grace means that history is open and that there can be no eschatological timetable. True prophecy accordingly, does not so much predict the future as isolate one possible course of events, one which can be communicated either as a warning, which may or may not, be heeded, or as a promise whose conditions may or may not, be met.
The heart of eschatology is not when or what, but Who, not a schedule or a plan, but a person. The role of the Gospels, culminating in, The Book of Revelation of Jesus Christ is to move us to contemplate the future not by giving us a blueprint, but by relating all to Jesus, Messiah and Son of Man.
For more reading: D.C. Allison, Jr. The End of the Ages has Come (Philadelphia; Fortress, 1985) GR Beasley-Murray, Jesus and the Kingdom of God(Grand Rapids; Eerdmans, 1986); H. Conzelmann, The Theology of St. Luke (London: Faberand Faber 1960); C. H. Dodd, The Apostolic Preaching and its Developments New York: Willett, Clark, 1937) E.E.Ellis, Eschatology in Luke FBBS 30; Philadelphia, Fortress, 1972); J Jeremias, The Parables of Jesus (2nd rev. ed.; New York: Charles Scibner's Sons, 1972) A.J. Mattill, Jr., Luke and the last Things (Dillsboro: Western North Carolina, 1979); N. Perrin, Jesus and the Language of the Kingdom (Philadelphia, Fortress, 1976); W. Willis, ed., The Kingdom of God in 20th Century Interpretation (Peabody, MA; Hendrickson, 1987)