Revelation 16:20-21

²⁰ And every island fled and no mountains could be found.

• Mountains are nations or kingdoms. Islands are smaller divisions of governments and ideologies. So we are shown that the world's divisions will end. Jesus will unite the entire world under His physical rule.
• Jesus will rule all nations after His return. There will be no more division of governments or economies. 

²¹ And great (excessively oppressive) hailstones, as heavy as a talent [between fifty and sixty pounds], of immense size, fell from the sky on the people; and men blasphemed God for the plague of the hail, so very great was [the torture] of that plague.

• Hailstones are used to show God’s destroying things.
• When Jesus returns all of the systems of Babylon, the trust in governments, the lie of worldly riches, and fake religions will all be wiped out quickly.
• People will morn because they will have no idea of what is happening. Their fear will be turned to joy though as Jesus begins His Rule and peace ensues.
• Yet remember that Jesus will have to rule with a Rod of Iron, there will be many who still won't accept the Truth that will set them free.
• Things will only completely change after Jesus Millennial Reign.