Composer Arvo Part, in an interview given in 1978: “There maybe exists the greatest teacher of all, I mean, the future – or let’s say, conscience. View yourself – what you’d really like to be. What you aren’t, but how you’d like to see yourself.”
Conscience is the present conviction of our future self. But how can we discriminate the certain pull of our better self from the deluded longing of mere fancy? Subjectively, this is impossible. Conscience is only a compelling judge if it subsists beyond our own subjectivity, if it is the actual presence of the future bringing holy freedom into our present. So, plug in John 16:8: “καὶ ἐλθὼν ἐκεῖνος ἐλέγξει τὸν κόσμον περὶ ἁμαρτίας καὶ περὶ δικαιοσύνης καὶπερὶ κρίσεως.” (“And when that one [the Comforter] comes, he will convict the world concerning sin and concerning justice and concerning judgment.”) Scripture is clear that the voice of conscience is the voice of the Holy Spirit, and this is why Robert Jenson is absolutely right to insist that the Spirit is God’s future, the present possibility of the eschatological peace to come.