Ten duplications give a sense of organization to the book: (1) two royal banquets (1:1-8), (2) two banquets for women (1:9-12; 2:18), (3) two listings of royal servants (1:10, 14), (4) two references to Esther concealing her identity (2:10, 20), (5) two references to virgins (2:8, 19), (6) two houses (2:12-14), (7) two royal consultations with leaders (1:13-20; 2:2-4), (8) and two with groups (6:1-5; 7:9), (9) Mordecai consulted twice with Esther (4:5-9, 10-17), and (10) Haman consulted twice with his wife and friends (5:10-14; 6:12-14).
These duplications serve as literary “stitches” that tie the narrative together.
Esther has always caused biblical scholars embarrassment because none of the names of God occur in the book. A recent computer search made by James D. Price and Leroy E. Eimers (see bibliography) has brought forth eight instances of four different divine names. These acrostics occur in 1:20; 4:9; 5:4, 13; 6:1, 14; 7:5, 7, all crucial spots in the story.
The theological themes in Esther seem almost as hidden as God himself. Much as in the story of Joseph (Ge 37, 39-50), the activity of God is providential. God is at work behind the scenes, overruling the decrees of potentates and wicked people, bringing about crucial turns of events, and always watching over his people to preserve them in times of crisis. It is this providential presence of God that has convinced both Jews and Christians that the book belongs in the OT canon.
As the story of Joseph ignores the polytheism of Egypt, so the book of Esther ignores the polytheism of Persia, except for passing reference to wise men who were astrologers. Both stories largely ignore the standard religious practices of the Hebrew people, especially those related to the priesthood. As noted above, the book does have two references to fasting, which would have religious significance. Even the Feast of Purim was set up as a folk observance with little religious significance.