Promise and fulfilment. Salvation-history and typology are connected also with the thematic polarity of promise-fulfilment. There are many variations on this theme, but essentially it goes beyond the fulfilment of promise or prophecy within OT history, and extends it to a definitive fulfilment in the NT. One implication of this is that the OT is incomplete with respect to the working out of God’s purposes and thus cannot be fully understood apart from its fulfilment in the NT. The two Testaments are interdependent in that the New is needed to complete the Old, but also needs the Old to show what it is that is being fulfilled.
Goldsworthy, G. (2000). Relationship of Old Testament and New Testament. In T. D. Alexander & B. S. Rosner (Eds.), New Dictionary of Biblical Theology