The greatest sins were idolatry and an unwillingness to follow God's teaching. They were evident among both Judah and the surrounding nations that threatened to defeat Judah. All would face God's punishment. Interestingly, there is a special warning in Zephaniah for the wealthy, who believed that riches would allow them to ride out any changes.
Through these overwhelming punishments, God's chosen people would again recognize the power and glory of God, and they would return to be God's people. They would follow God's laws and leave in peace.