18:8
Therefore in one day her plagues will overtake her:
death, mourning and famine.
She will be consumed by fire,
for mighty is the Lord God who judges her.
The reason is the Babylonian pride that visibly shows itself in glorifying oneself (previous verse). Self becomes the idol or god and this is the quickest way to "irritate" God (Exodus 20:1-5-6).
In the case of Belshazzar, as Daniel saw this in Daniel 5:17-30-31, the judgment happened very quickly later that night. So, too, this judgment happens "in one day". Babylon will be destroyed as fast as Sodom and Gomorrah was destroyed according to Isaiah 13:17-22.
death, mourning and famine.| Judgment | Loss of | Weakens | Reference |
| death | righteousness | spirit | 2 Samuel 24:10-17 |
| mourning | joy/comfort | will | Nehemiah 8:1-10-12 |
| famine | sustenance | body | John 6:22-40 |
Combine these weaknesses and death results both physically and spiritually.
She will be consumed by fire,
Anything which turns us away from God will be tested (1 Corinthians 3:10-13-15).
Anything related to the pride/glorification will be consumed (Hebrews 12:18-29).
Anything seen by Jesus Christ will be judged (Revelation 1:14).
Many times Babylon is referred to as GREAT (verses 2, 10, 19, 21) and thus implying STRONG. But the LORD GOD IS STRONG eternally (implying greater than Babylon). The LORD GOD will complete what was started in the seventh trumpet (Revelation 11:15-18).