There are certain texts that are familiar or at least ought to be. They teach us the place in history occupied by the New Testament or, more precisely, the new covenant economy (Gal. 4:4; Heb. 9:26; 1 Cor. 10:11). The New Testament era is ‘the fulness of the time’, ‘the consummation of the ages’, ‘the end of the ages’, the consummating era of this world’s history. Correlative with this characterization is ‘the last days’ (Acts 2:17; Heb. 1:2; 1 John 2:18). These began with the coming of Christ: So the world period is the last days.
This implies ages of this world’s history that were not the last days; they were prior, preparatory, anticipatory. The last days are characterized by two comings, notable, unprecedented, indeed astounding—the coming into the world of the Son of God and the Spirit of God. In order to accentuate the marvel of these comings we must say that God came into the world, first in the person of the Son and then in the person of the Holy Spirit. They came by radically different modes and for different functions. But both are spoken of as comings and they are both epochal events. These comings not only introduce and characterize the last days; they create or constitute it. —John Murray, The Unity of the Old and New Testaments