Jürgen Moltmann:
(c) The history which is initiated and determined by [God’s] promise does not consist in cyclic recurrence, but has a definite turn towards the promised and outstanding fulfillment. This irreversible direction is not determined by the urge of vague forces or by the emergence of laws of its own, but by the word of direction that points us to the free power and the faithfulness of God. It is not evolution, progress, and advance that separate time into yesterday and tomorrow, but the word of promise cuts into events and divides reality into one reality which is passing and can be left behind, and another which must be expected and sought. The meaning of past and the meaning of future comes to light in the word of promise.
(d) If the word is a word of promise, then that means that this word has not yet found a reality congruous with it, but that on the contrary it stands in contradiction to the reality open to experience now and heretofore. It is only for that reason that the word of promise can give rise to the doubt that measures the word by the standard of given reality. And it is only for that reason that this word can give rise to the faith that measures present reality by the standard of the word. “Future” is here a designation of that reality in which the word of promise finds its counterpart, its answer, and its fulfillment, in which it discovers or creates a reality which accords with it and in which it comes to rest.
(e) The word of promise therefore always creates an interval of tension between the uttering and the redeeming of the promise. In so doing it provides man with a peculiar area of freedom to obey or disobey, to be hopeful or resigned. The promise institutes this period and obviously stands in correspondence with what happens in it. This, as [Walther] Zimmerli has illuminatingly pointed out, distinguishes the promise from the prophecies of a Cassandra and differentiates the resulting expectation of history from belief in fate.
(f) If the promise is not regarded abstractly apart from the God who promises, but its fulfillment is entrusted directly to God in his freedom and faithfulness, then there can be no burning interest in constructing a hard and fast juridical system of historical necessities according to a scheme of promise and fulfillment—neither by demonstrating the functioning of such a schema in the past nor by making calculations for the future. Rather, the fulfillments can very well contain an element of newness and surprise over against the promise as it was received.