For you yourselves know that the day of the Lord so comes as a thief in the night.
1 Thessalonians 5:2
In the Scriptures, the exhortation to prepare for the day of the Lord is usually given to God’s people, rather than to unbelievers. Christians must be prepared for Christ’s return, so that they can properly respond to Him. The most important thing about the day of the Lord is clear: it comes unexpectedly. In Scripture, there are several references to the day of the Lord. Often this refers to Jesus’ first coming or His second coming, but it can also refer to any time God comes to His people, either in salvation or judgment (Isa. 13:6; Joel 2:11; Mal. 3:2).

