Vos: The Chief Actor came upon the Scene and occupied central place
How often have we heard a sermon on Galatians 4:4, and listened to the preacher wax eloquent on how the timing of Christ's birth was simply perfect? The Greek language was universal, the Roman infrastructure was pervasive, communication via pen had become common, somebody had finally invented crucifixion as a means of execution, etc. Sometimes it sounds a bit like Christianized astrology: "When the stars and planets were finally aligned, God sent His Son." Things were simply peachy-keen for the Father to send the Son to fix the mess.
In his "Pauline Eshcatology", Vos puts this utilitarian notion to rest:
“...the 'fullness of time' has nothing to do in the first place with the idea of 'ripeness of the times'; it designates the arrival of the present dispensation of time at its predetermined goal of fulfillment through the appearance of the Messiah (Gal. 4:4; see also Eph. 1:10.
“This straight horizontal way of looking at the eschatological progress was not with Paul a purely-formal thing. There belongs to it a grandiose sweep and impressive inclusiveness with regard to the whole of history. When filled with the content of the latter it acquires the character of the most intense dramatic realism." (Vos, The Pauline Eschatology, p. 26)
Vos is pointing out that "eschatological progress", or the progress of revelation and redemption toward its end goal in Christ and his resolution of all things in the New Heavens and New Earth, is "filled" up with the content of history. The events of history that have been recorded in the Bible, especially those in the Old Testament, are even better than real. Those events, even those that would seem mundane, are supernatural. They really happened, but they happened by design to bring about God's salvation of His people in Christ.
Long before Vanhoozer and Horton, Vos posits that this progress of redemption through the stages of history is a divine "drama", the one grand story of Jesus unfolding in the events and words of Scripture:
"It is drama, and, besides that, drama hastening on with accelerated movement to the point of denouement and consummation. Hence it engages the Apostle’s most practical religious interest no less than that it moulds his theoretical view concerning the structure of the Christian faith.
“…to Paul the chief actor in this drama had come upon the scene; the Messiah had been made present, and could not but be looked upon as henceforth the dominating figure in all further developments. And Christ was to Paul so close, so all-comprehensive and all-pervasive, that nothing could remain peripheral wherein He occupied the central place…" (Vos, The Pauline Eschatology, pp. 27-28)
It wasn't that 4 B.C. or 6 B.C. or whenever it is that Christ actually left the heavens and took on the lot of humanity that things were just so perfect Christ finally could get done what he needed to do. Such an idea reduces Jesus to simply another actor on the stage with the Father reacting to the hand he and the Son had been dealt. In fact, Galatians 4:4's language mitigates against this. "Completion" connotes the sense of something being brought to an end or a climax.
"Fullness" is the word used by the ESV. All of the events and revealed words of the Old Testament had been filled up and brought to their end goal: Jesus. "Fullness" like "completion", carries the sense of being filled up to having nothing more left to reveal regarding redemption. Paul sees salvation history like a cup, being filled to overflowing of all the historical events or acts and God's self-revelation in Scripture that were orchestrated by God to bring about the Person and work of Jesus.
When all of those Messianically-charged historical events, people, shadows, rituals, poetry, prophecy, and revelation reached their "fullness", Christ came as the Final Act of fulfillment on center stage.
Christ occupies the "central place" of this grand drama of redemption. The Incarnation is everything. In the Incarnation, Christ takes center stage of all of history, "filling up" the meaning of all of reality. Vos is right to suggest that this "filling up" includes the "eschatological progress" of Old Testament revelation and redemption.
So what? If Christ fills up the meaning of all of history, whatever happens today, good or bad, has meaning. It finds its meaning in who Christ is, what Christ has done for His people, and who I am in him. It also means that whatever happens today is within the scope of Jesus working to bring history to its ultimate conclusion. It may not look pretty today. It may be filled with sorrow and a temporary sense of senselessness. But it will not always be. The One who took on flesh in the fullness of time is the consummate Alpha and Omega. Time and its history find their meaning in Jesus. That's real hope... in the Fullness of Time.