Heilsgeschichte and promise-fulfillment are helpful ways of reading through the Old Testament in light of the New. However, John Bright provides some needed caution for avoiding either of these as hermeneutical magic bullets.
"The truth of the matter is that, however legitimate it may be—and is—to understand the relationship of the Testaments in terms of Heilsgeschichte or promise-fulfillment, neither formulation, unless defined very broadly indeed, is alone adequate to cover the case. Certainly the whole Old Testament cannot neatly be classified as promise, the whole of the New as fulfillment. If there is promise in the Old testament, there is also an element of fulfillment; and if there is fulfillment in the New Testament, there is also promise of things yet to come. More than that, there is much in the Old Testament that only by stretching terms beyond recognition can be labeled promise, and much more that is indeed promise but that finds no fulfillment in the New Testament or elsewhere—and indeed not a little that is abrogated in the New Testament. equally, the entire Old Testament cannot be subsumed under the rubric of Heilsgeschichte: there is much in it that fits in that category loosely, or not at all. The Old testament both is , and is not a Heilsgeschichte. It is, in that it focuses upon that saving purpose which announces as accomplished in Jesus Christ. But the history of Israel, of which the Old testament also tells, was not in itself a Heilsgeschichte but a very human history, and like all human history marked by nobility and greatness, yes, but also by sin and stupidity, questioning and rebellion, tragedy and frustration of hope. It is a history that led on to Christ—and equally to the rejection of Christ."
John Bright, The Authority of the Old Testament (London: SCM Press, 1967), 196.