Appropriately for this liturgical season, my graduate seminar has been reading Joseph Ratzinger's great work, Eschatology: Death and Eternal Life. Here is a passage:
In all human love there is an implicit appeal to eternity, even though love between two human beings can never satisfy that appeal. In Christ, God enters our search for love and its ultimate meaning, and does so in a human way. God's dialogue with us becomes truly human, since God conducts his part as man. Conversely, the dialogue of human beings with each other now becomes a vehicle for the life everlasting, since in the communion of saints it is drawn up into the dialogue of the Trinity itself.This is why the communion of saints is the locus where eternity becomes accessible for us. Eternal life does not isolate a person, but leads him or her out of isolation into true unity with their brothers and sisters and the whole of God's creation.