This Sunday's Gospel reading calls us to be ready in an urgent way. The doctrine of the second coming is not everyone's favourite, and perhaps suffers from the over-simplistic interpretation of fundamentalism, but "He will come again" is a creedal statement which is one of the building blocks of our faith. Advent Sunday focuses us on that future coming, which completes the cycle begun with Christ's first coming into the world. Did Jesus' disciples expect it to happen in their lifetime? Certainly, at least for the first few years. Did Jesus expect it to? Not necessarily. Despite the urgency of this saying, "no-one knows the day or the hour" is a prophetic statement which not only rules out any predictions of the end of the world, but also calls the disciples to a constant state of spiritual readiness, and is good for all generations, not just the first.
The working out of this spirituality is seen in Romans 13. While Matthew reminds us that the return of Christ will bring judgement for some, like the biblical flood, Christians should not assume that salvation is a ticket to put their feet up wait for the show. Paul says that believers remember that "the day is almost here", and this is like a trumpet calling us out of a deep sleep, spurring us on to holiness and a profound, all-consuming love for our neighbour which stems from a desire to please our returning Lord.
And the day that is coming is nothing less than a new world. Isaiah, seeing further than his contemporaries realised (and further than some commentators give him credit for), gives us a vision of a world where war is no more, because the God of Israel rules. The second coming is no comic-book caricature of a doctrine. We believe nothing less than that the God who made the world will one day re-create it, and when that day comes everything will cease, but all that has been will be gathered up and re-made into a newer and better reality.
No wonder Isaiah, Paul and Matthew all say "wake up, and walk in the light of the dawning day".