NOTES for Luk 12:32-40
The Saviour often speaks of the master's return—meaning, as one may readily guess, Himself—as an unexpected event. Although this unexpectedness may itself be expected, judging by Jesus' words it is quite possible that those waiting will be unprepared to meet the One they await. Why is this? Much can of course be explained by uncertainty about the time: it is not easy to keep oneself constantly ready; this demands too much inward strain.
Jesus Himself does not regard that argument as an excuse. He says plainly that if the householder knew when the thief would try to break into his house, life would be much easier—but, alas, that is not how things are. Nevertheless, if the householder wants to protect his house, he must always be on his guard. So must the servants awaiting their master, unless they want trouble from their unexpectedly returning lord. Clearly, a Christian's spiritual life requires constant spiritual alertness, without which one cannot remain in the Kingdom. Of course, one could say that any serious spiritual or ascetic system requires the same of its adherents. It could hardly be otherwise: this is a spiritual path, on which all kinds of unexpected things are possible.
Moreover, without maintaining spiritual alertness, we can forget about moving forward: every step on a spiritual path requires effort, as does the very ability to hold the new position reached through that effort. Otherwise, if a person relaxes spiritually, they can easily slide back to their former state. But spiritual alertness has special significance for life in the Kingdom. In the age of the advancing Kingdom, every inhabitant of it inevitably stands on the boundary between two worlds. Without the necessary efforts, one can easily fall out of the Kingdom's spiritual realm and find oneself wholly under the power of the evil in which the untransformed world lies.
Then there can no longer be any question of readiness to meet the Risen One. One cannot prepare for that meeting in a single instant: a spiritual process involving the transformation of human nature is required. For that process we have been given the time between the Saviour's coming into the world and His future return in glory. What the meeting will be like depends on how we use that time.