''....the day of the Lord will come like a thief in the night.'' The day of the Lord...

The question is asking about the meaning of the phrase "the day of the Lord will come like a thief in the night." This phrase is from the Bible, specifically 1 Thessalonians 5:2. The question wants to know what "the day of the Lord" means in this context.

Option A suggests that "the day of the Lord" refers to retribution. Retribution means punishment for wrongdoing. Option B suggests that it refers to repentance. Repentance means feeling regret or remorse for one's actions and seeking forgiveness. Option D suggests that it refers to tribulation, which means suffering or distress.

However, the correct answer is Option C, which suggests that "the day of the Lord" refers to judgment. Judgment means the process of forming an opinion or evaluation by discerning and comparing. In this context, it refers to the judgment of God over humankind. The phrase "like a thief in the night" suggests that this day will come unexpectedly and suddenly, without warning.

Overall, the phrase "the day of the Lord will come like a thief in the night" means that the judgment of God over humankind will come suddenly and unexpectedly, without warning. To learn more about this, please read the relevant sections of the recommended textbooks.