The heaviness of God’s judgment should show to us the greatness of his people’s sin. Their punishment is greater than Sodom's (Genesis 18:1 – 19:38). This is because Sodom was wiped out in an instant, while Jerusalem’s destruction was slow and devastating. The city was under siege for a year and a half, during which time many people died of hunger. Then the city was destroyed by murderous soldiers, and the people who did not die of the sword would die in time from disease and hunger.
If Jerusalem’s punishment was worse than Sodom's, then the implication is that Jerusalem’s sin was also worse than Sodom’s sin. This is confirmed by other Bible passages (Isaiah 1:10; Ezekiel 16:46–47). Also, remember that Israel was God’s chosen people. It is a biblical principle that “from everyone who has been given much, much will be demanded” (Luke 12:48).
6 For the chastisement of the daughter of my people has been greater than the punishment of Sodom, which was overthrown in a moment, and no hands were wrung for her.