The Day of the Lord

"The Day of the LORD” is a biblical term and theme used in both the Hebrew Bible (יֹום יְהוָה Yom Adonai) and the New Testament (ἡμέρα κυρίου, hēmera Kyriou), as in "The sun shall be turned into darkness, and the moon into blood, before the great and the terrible day of the LORD come" (Joel 2:31, cited in Acts 2:20).

In the Hebrew Bible, the meaning of the phrases refers to temporal events such as the invasion of a foreign army, the capture of a city and the suffering that befalls the inhabitants.

The prophet Malachi foretells the return of Elijah immediately preceding the "great and terrible day of the LORD".

Thus, the day of the Lord is about God chastening his people, whether it be through the Babylonian invasion of Jerusalem or a locust plague described in Joel 2:1–11.

The Book of Revelation describes the day of the Lord as an apocalyptic time of God's almighty wrath, which comes upon those who are deemed wicked.

10But the day of the Lord will come as a thief in the night, in which the heavens will pass away with a great noise, and the elements will melt with fervent heat; both the earth and the works that are in it will be burned up.

[11] The Didaché, the earliest Christian testimony, says "Come together on the Lord's Day, break bread and celebrate thanksgiving".