The leading concept of the book of Zephaniah is the coming of the Day of Yahweh. This image, which may have risen out of the theology of the tribal league, emphasized the ominous nature of the manifestation of Yahweh. He comes to fight for and deliver his people Israel. Popular thought viewed the day as one when God would defeat Israel's enemies and establish her as the supreme military power (Am 5:18). The prophets widened this expectation to include the visitation of Yahweh's wrath on all the sinful, including the chosen people themselves. The nation by which God would bring judgment is not mentioned. The older theory, based on a statement of the Greek historian Herodotus, that Zephaniah saw the invasion of the Scythians as the judgment of God, has now been generally rejected. Like Amos and Hosea, Zephaniah leaves undefined the exact instrument of Yahweh's wrath.
Zephaniah's catalogue of the sins of humanity is not extensive. Judah is indicted for idolatry (1:4-9), sinful pride (1:12; 3:2), and oppression through perversion of the law (3:3-5). The nations are guilty of hubris or pride (2:8, 15), scornful of the rest of humanity. Yahweh desires humility in righteousness and sets himself as the defender of those who humble themselves before him (2:3; 3:12).
The major theological theme that unites the book is that of the presence of Yahweh. That presence may be manifested either in judgment or salvation, depending on the spiritual condition of the people and the purpose of God. The judgment visited upon Judah and Jerusalem conforms to the conditions of the Mosaic covenant, which Yahweh had committed himself to observe (Dt 28:30, 39). The curses of the covenant, however, are remedial (Dt 30:1-6). God's purpose is to restore the people to righteousness in order to dwell in their midst (3:15, 17). In Zephaniah the covenant has not yet been democratized so that those nations that lie outside the covenant experience only the judgment of Yahweh with no hope of restoration (2:5, 9, 12, 13).