Then the kingdom of heaven shall be likened to ten virgins who took their lamps and went out to meet the bridegroom. Now five of them were wise, and five were foolish. Those who were foolish took their lamps and took no oil with them....And at midnight a cry was heard: "Behold, the bridegroom is coming; go out to meet him!"...And while they [the foolish] went to buy [oil], the bridegroom came, and those who were ready went in with him to the wedding and the door was shut. Matt. 25:1-10, NKJV.
The third parable on preparedness for the Second Advent (Matt. 25:1-13) continues the theme of waiting in watchful expectation, but once again the complexity of the message increases. This time the scene is a Palestinian wedding with Jesus as the Bridegroom.
Beyond the coming of the Bridegroom, the focus of the parable is on the 10 virgins and their lamps. In fact, the primary emphasis is really on the division between the virgins, with five being wise and five foolish. The difference between them has to do with the preparation they have made for the coming of the Bridegroom. All have lamps, but only half of them have sufficient oil.
Note that all 10 are outwardly Christians, for all of them are awaiting the Bridegroom. Also recognize that all 10 fall asleep.
A major point in the parable that we can all identify with is that the Bridegroom is "a long time in coming" (verse 5, NIV). That is why they are sleeping. Earthly necessities go on, even while Christ's followers anticipate His return. No one can exist in a constant state of high-pitched alert. And His delay tempts them to forget His return while they focus on the activities of the world. All sleep.
The difference between the wise and the foolish is not sleep but rather preparation for the return. Some have left preparation for the last minute, when it is too late. They pay deeply for their neglect. The door is shut (verse 10), their probation has closed (cf. Rev. 22:10, 11), and they miss the great "wedding supper of the Lamb" (Rev. 19:9, NIV) that takes place at the Second Advent (Matt. 25:11, 12).
Verse 13 gives the moral of the story: "Keep watch, because you do not know the day or the hour" (NIV). That theme, of course, undergirded the first two parables. But this one adds the facts of a long delay and that no individual can rely on another person's preparedness. In the judgment of God each one of us stands as an individual.