What does Revelation 18:15 mean?

Knowing how terrible a fate Babylon experienced, the merchants who had profited from selling expensive items to her residents stay clear of Babylon as the city burns to the ground. The merchants fear that they might experience a similar judgment. So, their tears flow in torrents and their mourning reaches a high volume. Although the Scripture does not tell us every reason the merchants mourn, we can guess from these depictions what was most important to them: profit. Their main lament is over business losses and not the loss of life in the judgment on Babylon.

The apostle John offered sound counsel to his readers about establishing correct priorities. He exhorted them and us: "Do not love the world or the things in the world. If anyone loves the world, the love of the Father is not in him. For all that is in the world—the desires of the flesh and the desires of the eyes and pride of life—is not from the Father but is of the world. And the world is passing away along with its desires, but whoever does the will of God abides forever" (1 John 2:15–17).

If we want something that lasts throughout eternity, we ought to obey God, because the rewards of faithful service endure forever. Everything the evil world system deems important is already deteriorating and ultimately will vanish.