Eschatology was long called the ‘doctrine of the last things’ or the ‘doctrine of the end.’ By these last things were meant events which will one day break upon man, history and the word at the end of time. They included the return of Christ in universal glory, the judgment of the world and the consummation of the kingdom , the general resurrection of the dead and the new creation of all things. … But the relegating of these events to the ‘last day’ robbed them of their significance for all the days which are spent here, this side of the end, in history. … In actual fact eschatology means the doctrine of the Christian hope, which embraces both the object hoped for and also the hope inspired by it. From first to last, Christianity is eschatology, is hope, forward looking and forward moving, and therefore also revolutionizing and also transforming the present. The eschatological is not one element of Christianity, but it is the medium of Christian faith as such, the key in which everything in it is set, the glow that suffuses everything here in the dawn of an expected new day. For Christian faith lives from the raising of the crucified Christ, and strains after the promises of the universal future of Christ… The element of otherness that encounters us in the hope of the Old and New Testaments – the thing we cannot already think out and picture for ourselves on the basis of the given world and of the experiences we already have of that world – is one that confronts us with a promise of something new and with the hope of a future given by God. The God spoken of here is the ‘God of hope’ (Rom 15.13), a God with ‘future as his essential nature’ (as Bloch puts it) as made known in Exodus and in Israelite prophecy . A proper theology would therefore have to be constructed in light of its future goal. Eschatology should not be its end, but its beginning.
There is therefore only one real problem in Christian theology: the problem of the future. … But how, then can Christian eschatology give expression to the future? Christian eschatology does not speak of the future as such. It sets out from a definite reality in history and announces the future of that reality, its future possibilities and its power over the future. Christian eschatology speaks of Jesus Christ and his future. It recognizes the reality of the raising of Jesus and proclaims the future of the risen Lord.
Quoted from Theology of Hope, pp. 15-17