Why is God's name not mentioned in the Book of Esther

Why is God's name not mentioned in Esther- especially in obvious places like this one? Scholars suggest several answers to this riddle. Some, reading between the lines, suggest that Esther and Mordecai were not outstanding examples of faith. 

They were even not outstanding examples of faith. They were willing to hide Esther's Jewish background. Esther showed no reluctance to be married to a pagan king and become part of his harem. Most critically, she and Mordecai(along with all the other Jews in Esther) had chosen not to return to Jerusalem with the first wave of Jews nearly half a century before. Those who stayed in Persia presumably cared more about to return to Jerusalem from exile. Perhaps because of this, Esther is told as a secular story, to illustrate God's care over even "secularized" Jews.

The purpose of the Book of Esther is to display the providence of God, especially in regard to His chosen people, Israel. The Book of Esther records the institution of the Feast of Purim and the obligation of its perpetual observation. The Book of Esther was read at the Feast of Purim to commemorate the great deliverance of the Jewish nation brought about by God through Esther. Jews today still read Esther during Purim.

Key Verses:Esther 2:15- Now when the time came for Esther to go to the king, she asked for nothing other than what Hegai, the king's eunuch who was in charge of the harem, suggested.

Esther 4:14- For if you remain silent at this time, relief and deliverance will arise from another place, but you and your father's family will perish. And who knows but that you have come to the royal position for such a time as this.

Esther 6:12- Since Mordecai, before whom your downfall has begun, is of Jewish origin, you cannot stand against him - you will surely come to ruin!

Esther 7:3- If I have found favor with you, O king, and if it pleases your majesty, grant me my life - this is my petition, and the life of my people - this is my request.