Love is the ultimate reality, and it is not visible except as continuity. In a word, the proof that I am dealing with the real world is the experience of the continuity and perseverance of love. That persons be faithful to God and to each other is the overriding proof that we are dealing with love, and therefore, with reality.
Ratzinger-Benedict XVI writes: "Love is the criterion of the Holy Spirit as against unholy spirits... The basic criterion of love, its 'proper work,' so to speak... is this, that it achieves abiding. Love shows itself by being enduring. It can by no means be recognized at a given moment and in the moment alone; but in abiding, it does away with uncertainty and carries eternity within it. And thus in my view the relationship between love and truth is also thereby given: love, in the full sense, can be present only where something is enduring, where something abides. Because it has to do with abiding, it can occur, not just anywhere, but only there where eternity is" (Pilgrim Fellowship of Faith 44-45).