The ‘day of the Lord’ is an event that takes place at the end of history. The end of history—let that sink in. There is a day coming when our Lord Jesus Christ will call an end to this earth. The sermon text, Revelation 6:15-17, spells out what is going to happen when the ‘wrath of the Lamb’ is visited on mankind.
It's an awakening for those who didn’t heed all the warnings about this day that are cited in the Bible. One of the early ones is Isaiah 13:6, “Howl ye; for the day of the Lord is at hand; it shall come as a destruction from the Almighty.” One of the later ones is II Peter 3:10, “But the day of the Lord will come as a thief in the night…” Of course, there are many others in between. (I came up with 38. You may find more.)
It's much like the same thing as all the warnings we get about bad weather. They keep saying, “Get ready. We’re going to have floods.” Some take it seriously and others don’t. The same thing is at play here. Somehow, we’ll get lucky and dodge the bullet.
Not so here in Revelation 5:15. The sinners, hypocrites, proud, and rich will suffer the wrath of the Lamb (verse 16, 17). Remember that we serve a just, holy, and righteous God.
God also is gracious and merciful. Those who are on the treadmill of sin and sinful ways can always call out to God. Heed the warnings. God can save you. Only He can save you from the wrath to come.