From Second Corinthians by Thomas J. Stegman, SJ, reflecting on 2 Cor. 13:11-13:
The doctrine of God as one and triune took hundreds of years to be fully formulated. What Paul’s writings reveal, at a remarkably early period—recall that he wrote 2 Corinthians only a quarter century after the death and resurrection of Christ—is an extraordinarily rich appreciation of what theologians call the “economic Trinity,” that is, God revealed in his activity in history through the sending of his Son and the outpouring of his Spirit. One prominent Pauline scholar refers to Paul’s benediction in 2 Cor 13:13 as “the most profound theological moment in the Pauline corpus” (Gordon D. Fee, God’s Empowering Presnce). The Apostle’s blessing here contains in embryonic form the rich understanding of the Trinity formulated in the Church’s great ecumenical councils.