In his Letter to the Ephesians Paul exulted in the fact that God had chosen him and the Apostles to make known the great mystery underlying all creation: namely, that it is God’s will to bring all of creation together in Christ.
One wonders how that could be. We might ask, “Since Jesus lived and died two thousand years ago, what grand influence could he have on all the non-Christian infants to be born in Mongolia and Uganda?”
However, if we start at the other end of creation we can see some connection. I mean, John’s Gospel identified Jesus as the Word of God through whom all things came to be. John there implied that no living person comes to be except through the Word.
So, all of us, even the yet-to-be-born Mongolian and Ugandan babies, we were all together in Christ at the beginning of creation. How, though, can we be together at the end of creation?
I don’t know, but the Jesuit Teilhard de Chardin spoke of all creation eventually converging; and in line with St. John calling Christ the Alpha and the Omega, de Chardin hypothesized that by a reverse type of evolution all creation would converge at what he called the Omega point.
Paul said his revelation concerning God bringing us all together in Christ was a mystery, and perhaps we will need to leave it at that.