He shall judge between many peoples, and rebuke strong nations afar off; they shall beat their swords into plowshares, and their spears into pruning hooks; nation shall not lift up sword against nation, neither shall they learn war anymore. But everyone shall sit under his vine and under his fig tree, and no one shall make them afraid; for the mouth of the LORD of hosts has spoken.
Humanity has proven itself incapable of finding the way to peace. But after Jesus Christ returns to the earth and establishes the Kingdom of God, He and His followers will teach the way of peace. Implements of war will be transformed, and war colleges will be shut down.
The attainment of peace between nations will also be reflected by peace on a personal level, as people will enjoy their homes and gardens without fear of criminals or other dangers.
For more about peace and how it will come, see “1,000 Years—the Millennium.”