A thief does not announce when he intends to break into your home to steal your valuables. If he would announce his coming, you would certainly make a point of being ready for him so as to protect your belongings. The fact that he comes when you do not expect him makes you feel like a victim, taken advantage of. Unlike the thief, Jesus does announce that he is coming (though without stating his timing). Exactly because he is coming (Acts 1:11; 2 Thessalonians 1:10), saints in love with the gospel will be eagerly awaiting him so as not to be surprised at his coming (2 Peter 3:10–14; 1 Thessalonians 5:4; Matthew 24:36–51). If Christians are not alert and watchful (i.e., they are distracted in some way), they will experience Christ’s coming as “against you,” and such Christians (with a fine reputation!) will be victims of his judgment.
3 Remember, then, what you received and heard. Keep it, and repent. If you will not wake up, I will come like a thief, and you will not know at what hour I will come against you.