As Paul closed his letter to the churches in Galatia, he encouraged them saying, "And let us not be weary in well doing: for in due season we shall reap, if we faint not" (Galatians 6:9). The Bible is telling us to continue to do good because there will be a season of reaping.
We can often be discouraged because it seems we have continued to do good again and again, but it doesn't seem like there is any return for us. We may, in fact, feel like doing good is working against us. We need to remember the Bible says we will reap in due season.
An example of reaping good in due season is Esther's cousin Mordecai. A plot to murder King Ahasuerus became known to Mordecai, who reported it to Esther, and the king's life was saved (Esther 2:21-23). Mordecai didn't receive any honors, accolades, money, or promotion for saving the king's life. The event was simply recorded in the book of chronicles before the king.
In due season, when Haman was preparing to ask the king to execute Mordecai, the king could not sleep. The king called to have the book of chronicles read to him, and the event when Mordecai saved his life was read. The king asked if anything had been done for Mordecai, and his servants said no (Esther 6:1-3).
The king commanded Haman to placed Mordecai on the king's horse with a royal robe and a crown and have Haman lead Mordecai through the streets to honor him. Mordecai reaped good for the good that he had done to the king. If Mordecai had reaped good earlier for saving the king, the king would not have honored him. If Mordecai had been honored earlier, he would have lost his life when Haman came to see the king. Be not weary in well dong, for in due season we will reap if we faint not. God knows the season we need to reap in.