What does Psalm 118:24 mean?

Many believers are familiar with this expression. It is used in songs, poetry, church greetings, and artwork. Typically, the statement is interpreted to mean that "today" is God's creation, so we should celebrate it. That application is appropriate, given what Scripture says about thankfulness and joy through the Lord (Psalm 40:16; Philippians 4:4; Ephesians 5:20). Everyone who places trust in God (Psalm 84:12) has reason to be joyful no matter their circumstances (Romans 8:18, 28).

However, the original meaning of this statement might refer to a different meaning of "day." This is part of a series of psalms (Psalm 113—118) used during festivals such as Passover or the Feast of Booths (Deuteronomy 16:16). The psalmist may refer to the holiday as something the Lord has created, so it should be a source of rejoicing.

Another possibility is that "the day" is used in the prophetic sense. The Old Testament often speaks of God's ultimate victory over sin and death, or His return in judgment, as "that day," "the day," or "the day of the Lord" (Isaiah 2:12; Ezekiel 30:3; Joel 1:15; Amos 5:18; Obadiah 1:15; Zephaniah 1:7; Zechariah 14:1; Malachi 4:5). The same is true of the New Testament, where such references are almost always about the end times (Acts 2:20; 1 Corinthians 5:5; 2 Corinthians 1:14; 1 Thessalonians 5:2; 2 Thessalonians 2:2; 2 Peter 3:10; Revelation 6:17; 16:14). The kingdom age where Christ rules the world in person can also be described using such phrases (Isaiah 12:3–4; Micah 4:1–4).

Any or all of these meanings are reasonable ways to interpret this verse. Believers of the past, present, and future all have excellent reasons to rejoice in the Lord, every day.