Christ and the Day of the Lord come as a thief in the night, at an hour no one expects, purposefully hidden from all. The imagery does not call for scanning world events to calculate timing. Jesus says repeatedly that no one knows the day or hour, and after His resurrection He extends this to times and seasons (Acts 1:6-7). The thief's coming is a call to watch, and watching means staying sleepless and vigilant over one's own spiritual state, faithfully carrying out God-given duties like a servant keeping the Master's house in order (Luke 21:34-36; 12:35-40). A householder who knew the thief's hour would guard his house, so believers must always be ready. In the Parable of the Wise and Foolish Virgins, the midnight cry leaves no time to prepare, because the period of preparation has ended. Paul tells the Thessalonians that the Day comes as a thief, but those who are sons of light, sober and clothed in faith, love, and hope, need not be overtaken by its wrath, though it will still surprise them. Believers can still incur wrath if they neglect themselves (Hebrews 10:26-31). Christ warns the church in Sardis, which has a reputation for life but is spiritually near-dead, that if it will not watch, He will come as a thief and they will not know the hour. Even avid prophecy-watchers can be spiritually asleep. Faithfulness in the mundane and unexciting prepares one for the Day.

Jesus' comments about the thief teach that His disciples must be ready because the Son of Man will come unexpectedly (Luke 12:39-40; Matthew 24:42-44; 25:13; Mark 13:33; Revelation 3:3). The comparison lies in the story as a whole, not in the individual characters, so Christ is not likened to a thief in character; rather, His return, like a thief's arrival, comes at an hour no one expects. A homeowner who knew when a thief would come would stay awake and prevent the break-in, so disciples must stay watchful at all times. The unwise servant ignores this and makes two mistakes. He does whatever he wants while the master is away, forgetting that the day of judgment must come, and he assumes he has plenty of time to put things right before the master arrives. Assuming more time is among the most harmful presumptions (I Thessalonians 5:3). Because Christ's coming, like the thief's, cannot be predicted, readiness must be constant. Jesus Himself said the night is coming when no one can work (John 9:4).

Christ's return will come like a thief in the night, suddenly and without warning. Jesus used the image in Luke 12, saying that if the master of the house had known what hour the thief would come, he would have watched and not allowed his house to be broken into, so His servants must be ready, for the Son of Man comes at an hour they do not expect. Paul picks up this language in I Thessalonians 5:1-6, and Peter uses it in II Peter 3:10, where the day of the Lord comes as a thief and the heavens and earth are dissolved. Thieves send no advance notice, so break-ins are sudden and shocking, and Christ's return will be equally surprising to most people. It will come when the majority least expect Him, when the news announces "Peace and safety!" and the world is absorbed in the affairs of this life, and then destruction will come as suddenly as labor pains. Christians, however, are not in darkness, so the day should not overtake them as a thief. They are to watch by staying aware of the signs of the times and of trends and attitudes in the church, the world, and themselves. They are also to be sober, serious, thoughtful, cautious, and calm, keeping their minds clear and their eyes on God's Kingdom and righteousness. Scoffers who say Christ's coming is delayed are wrong, and believing that He is delayed leads to spiritual drifting.