The Day of the Lord is a phrase used in the Old Testament to describe God intervening in earthly affairs with judgment. For example, Babylon’s destruction of Egypt (Eze. 30:3) and Judah’s punishment for idolatry (Joel 1:15; Zeph. 1:7) are both referred to as the Day of the Lord.
The Bible also prophesies a future Day of the Lord that comprises both judgment and blessing. That period includes Daniel’s 70th week (Dan. 9:27), the battle of Armageddon (Joel 3:14), and Christ’s second advent. Israel’s restoration and the Millennial Kingdom follow Christ’s return, and are also prophesied as being “in that day.” (Isa. 2:12; 4:2-6; Zech. 14:1-21). The New Testament gives more light (Acts 2:20; 1 Th. 5:2; 2 Th. 2:2; 2 Pet 3:10-12), also describing how the destruction of heaven and earth, and the Great White Throne Judgment will close out that day (Jude 1:14-15; Rev 6-20).
The term “Day of the Lord” itself refers to an extended period of time in the same manner one might say “the day of our youth.” Yet because a 24-hour day contains both darkness and light, some also see symbolism in the expression. John Walvoord writes, “In 1 Thessalonians 5, the day of the Lord is used …of an extended period of time but having the characteristics of a twenty-four-hour day. That is, it is a day that begins…in the darkness, advances to dawn, and then to daylight. It will close again with another period of darkness after daylight has passed.”1
In other words, that day begins with tribulation (darkness), is followed by the millennium (light), and concludes with rebellion at the millennium’s end (darkness – Rev. 20:7-10). This view has merit for Scripture measures a day beginning and ending with darkness. For example, in Genesis 1:5 God said, “and the evening and the morning were the first day.” Likewise, from the beginning, the Jewish nation considered a day to be from evening to evening or sunset to sunset (Ex. 12:18; Lev. 23:32), as did other nations in antiquity.2
After the final rebellion, God will destroy heaven and earth, and time and day (natural light and darkness) will disappear. Then the believer will live forever in the endless light of God’s glory on a new heaven and earth (2 Pet. 3:13; Rev. 21:1; 22:5).
In contrast, the Day of Christ involves only His church, a heavenly people (Phil. 1:6, 10; 2:16; 1 Cor. 1:8; 2 Cor. 1:14; 1 Th. 2:19-20; Heb. 10:25). There will be no darkness in that day for we are children of light (1 Th. 5:5). It begins with Christ returning to the air for His church, the dead in Christ being resurrected, and the living believers putting on immortality (1 Cor. 15:51-58). Glorified, we shall ascend to heaven to individually appear before the judgment seat of Christ (Rom. 14:10; 1 Cor. 3:11-15; 2 Cor. 5:9-10). This is not a time for our sins to be judged (Jn. 5:24; Rom. 8:1), rather it’s a rewards ceremony for our service. After this, each believer is granted a radiant robe reflecting our righteous acts, to prepare for our marriage to Christ (Rev. 19:7-8). This period concludes with Christ returning to earth with His bride (Rev. 19:11-21).
Failure to differentiate between these two days leads to confusion when interpreting prophetic passages. For example, in 1 Thessalonians 5:1-4, Paul uses the idiom “times and seasons.” Since this passage concerns the Day of the Lord we know that “times and seasons” cannot relate to the rapture. Instead it consistently refers to periods and events on earth, to God raising up and removing Gentile powers, and restoring Israel’s kingdom (Dan 2:19-22; Lk. 21:24; Acts 1:7; 3:19). Similarly, the saying “thief in the night” (v. 2) substantiates the gospels’ use to speak of Christ’s second coming to judge the earth (Mt. 24:43; Lk. 12:39).
In summary, both the past and future Day of the Lord relates primarily to Israel and the nations on earth. Conversely, the future Day of Christ pertains to the completed church in heaven, a joyful time of fellowship and reward.
1. John F. Walvoord and Mark Hitchcock,1st & 2nd Thessalonians (Chicago, IL: Moody Publishers, 2012), p. 86-87
2. Merrill F. Unger, The New Unger’s Bible Dictionary (Chicago, IL: Moody Press, 1988), p. 1285-1286