Esther is a difficult book to contend with. Our tendency is to try to make everyone in the Bible into a hero, and so we try to make Esther out to be the female version of Daniel. Only she's not.
They were both exiles, but Daniel knew who he was and in whom he believed and he never backed down in his convictions. Daniel not only admitted that he was a Jew, but asked for concessions based on his Jewishness. He refused to bow down to any other gods and he prayed, even when prayer fell under the penalty of death.
Esther, on the other hand, does not have that kind of devotion to God. She and Mordecai have grown so comfortable in Persia that they do not return to their homeland in order to rebuild the walls along with the remnant, despite King Cyrus' decree. She goes by the Persian name Esther instead of her Jewish name of Hadassah, and hides her Jewishness from everyone. Mordecai seems to encourage her participation in a beauty contest which includes spending one night with a pagan king, and quite presumably, all that that would entail. As far as we know, she goes along with these plans willingly. When Mordecai finally confronts her with Haman's plans and forces her to make a decision, she doesn't want to do it. The fact that in the end she decides to go to the king does not necessarily speak to her courage, but more likely her desperation. Her choice, after all, was between certain death and possible death.
We like Daniel. Like the song says, we want to "dare to be a Daniel". But we're uncomfortable with Esther.
But the thing is - in reality, most of us are more like Esther than Daniel. Perhaps that's exactly what makes us uncomfortable. We look at her faults - willingness to compromise, materialistic, lack of devotion, focus on appearance, lack of courage - and we see them in ourselves. But that is the good news. God can use us, in spite of ourselves, in spite of our sin.
In his sermon, For Such a Slime as This, Hershael York says:
You need to understand that just because you don't see God in Esther that doesn't mean he's not there. And if there's anything you need to learn to trust, it's that you can trust that God is with you in spite of your dim vision. Sometimes your vision will be dimmed by your own sinfulness, sometimes by the circumstances, sometimes by the pain and grief that envelops you. But God does some of his best work in the shadows, hidden from view, obscured by the dim vision on those whom he is dealing with. I think for every Daniel who sees a clear vision of the Son of Man, there are a thousand Esthers who come stumbling, staggering, reluctantly dragged into the will of God by desperation and a lack of alternatives....
[We serve a] God who is so big that he can take the tragedies, the sorrows, even the sinful choices and decisions of your life and still weave them into the fabric of his purpose and plan for your life so that he gets glory from you anyway... That's the God who is hidden in Esther and yet displayed everywhere in Esther...
That's the God we serve. It's the God that has brought you through everything in your life—your failures and tragedies and grief and bad decisions and sinful choices. He has brought you to this moment so that you may come to him in your imperfect place and with your broken past, and you can know that the King of Kings holds out not a golden scepter but a bloody cross, and see that he is not hidden in the shadows but on his throne.