The Book of Esther is a curious book. For one thing, it is the only book in the Bible that never mentions God. For another, it is high up in the running for the most artfully constructed book of the Bible. The author's handling of plot is absolutely brilliant, and with my extremely limited knowledge of ancient literature I wonder if there is anything older that does the short story genre so exquisitely. (If you happen to know an example please enlighten me in the comments. And for clarification I don't believe that the story of Esther is fictional, but it is composed in a beautifully stylized fashion that resembles a fictional short story.)
One of the most important questions you can ask when studying the Bible, whether looking at a single word or an entire book, is, "What is it doing here?" In other words, the author could have written anything or even nothing, but he chose to write this particular thing, so why did he do it? The answer to that question often goes a very long way to understanding what is written.
There are probably a few reasons that Esther was written and then included in the biblical canon. One is to explain and/or commemorate where the Jewish holiday of Purim came from, especially since it was not one of the original national holidays that God ordained through Moses. Another reason is to give glory to the silent but ceaselessly working God who so orchestrated the entire series of events not only to save his people but also to elevate them in the eyes of the king of a vast empire.
But the reason for Esther that I want to explore a bit, which I happen to think is the principal reason that the book was written and preserved, is that Esther and Mordecai serve as a model for how the Jews are to survive the exile in which most of them have lived for lo, these many years.
Esther and Mordecai did three things that ensured their survival and the survival of their people in extreme circumstances.
1. They were careful about their identity but refused to compromise it. There is an interesting contrast early in the book when Mordecai warns Esther not to let anyone know that she is a Jew, but he himself defiantly disobeys the king's command to pay homage to Haman because Haman is descended from the Amaleki King Agag, whom the Israeli King Saul was supposed to destroy. Surprisingly, for Mordecai showing respect for Haman was a deal-breaker, a fundamental compromise of his Jewishness. (Incidentally, this reveals the regal character of Mordecai the Jew—that is, a man of the tribe of Judah—because he resembles David of the tribe of Judah in his faithfulness instead of Saul. It is no accident that the very last chapter of Esther sounds a lot like the summaries of reigns of kings of Israel and Judah in Kings and Chronicles [like this one].)
2. They loyally served the government where they found themselves. So what that the Medes and Persians were (for the time being) continuing the Babylonian policy of keeping the Jews out of their homeland. Esther not only showed the utmost submission to the king—think very seriously about what I'm talking about and read ch. 2 if you're not sure—but Mordecai saved his life.
3. They used their influence to benefit their people even at risk to their own lives. This is probably the motive that underlay Mordecai's refusal to bow down to the descendant of the enemy of his people despite the retribution that he knew he would get for it (but apparently didn't know that all the Jews would get). But of course, this behavior is what the entire book is about, encapsulated most dramatically in the conversation between Mordecai and Esther after Haman's decree culminating in Esther's resolve. Mordecai is praised for taking the same approach in his governmental service in ch. 10.
I've written (and more importantly, the Bible has written) about how we Christians are living in exile and therefore have much to learn from the Jews of the Diaspora. I admit, though, that this is complicated in the United States because it's hard to know whether we are exactly a minority as the Jews in the Persian Empire (and others) were. Is the number of Holy Spirit-regenerated believers less than half the total American population? Probably. Is the number of self-identified Christians in America a minority? No. Likewise, is Christianity the state religion in the U.S.? I would say no. Do concepts that stem from Christian-influenced philosophy form much of the basis of our system of government? I think they do. So it might not be appropriate us to parrot the example of Esther and Mordecai unthinkingly.
But I still think that there is much to learn from the three behaviors that they exhibited. As exiles, it is not okay for us to compromise our identity as servants of Christ, but it is okay for us to be judicious and careful about how widely to disclose that fact. For example, there could be workplaces where openly proclaiming your relationship to Christ is the best thing for the spread of the gospel there but others where doing so is likely to wall you off from any opportunities to share your faith and be taken seriously at all.
Also, I think it is important that we give Christians who serve the government loyally their due, especially in this anti-institutional age. Mordecai was a civil servant, which is why he was always hanging out at the gate of the palace (2:19; 3:2; 4:2). If you happen to be a conservative whose blood pressure rises at the thought of government bureaucracy, guess what: Mordecai was a bureaucrat. (Incidentally, so were Daniel, Hananiah, Mishael, Azariah, and Nehemiah.) Christians can serve the state and honor Christ in the bureaucracy (tough though it may be). And if you happen to be a liberal, have you prayed and thanked God for Christians in our armed forces today?
It's the last principle that I'm not sure what to do with. If Christians are continually in a precarious position where a momentary shift of hostility to us in the powers that be will result in our annihilation, then believers in positions of influence should look out for the rest of us. But if we compose a very large portion (even if not outright majority) of the population, then mightn't that agenda be unjust favoritism that does not honor God and actually hurts our witness to Christ? That's a tricky one in our situation I think.
But bottom line, we can learn a good deal from Esther and Mordecai and the other biblical Jews of the exile about how to live as aliens and strangers in this world that is not our home.