But when the fullness of time had come, God sent forth his Son, born of woman, born under the law, to redeem those who were under the law, so that we might receive adoption as sons. (Galatians 4:4-5, ESV)
What is meant by this "fulness of the time" is not only the maturation of a specific matter in the great framework of redemptive history, but the fulfillment of the time in an absolute sense.The time of the world has come to a conclusion with Christ's advent. However much this fulfillment still bears a provisional character and the perfectum is followed yet again by a futurum, nevertheless the pleroma of the time or of the times is here spoken of as a matter that has already taken effect and thus in principle has been settled.**
In Ephesians 1:9,10, Paul tells us that in Christ, God is "making known to us the mystery of his will, according to his purpose....as a plan for the fullness of time, to unite all things in him, things in heaven and things on earth. (ESV)".** Something is being summed up, completed, united, concluded in Christ.