Are you familiar with the African-American spiritual, "There Is a Balm in Gilead"?
"Sometimes I feel discouraged and think my work's in vain,
But then the Holy Spirit revives my soul again.
There is a balm in Gilead to make the wounded whole;
There is a balm in Gilead to heal the sin sick soul."
I wasn't familiar with it until I heard Martin Luther King's A Knock at Midnight speech, where he quotes the above verse at the end.
It's one of the most moving and inspiring speeches I've ever heard. Takes place years after the Montgomery Bus Boycott, when King soberly reflects on the overwhelming discouragement he sometimes felt as the leader of the Civil Rights movement (remember, Dr. King was only 26-27 years old at the time!).
I used to listen to this speech on repeat in my car when I first moved to LA 14 years ago, and found it particularly useful whenever I felt discouraged.
The entire recording is only about seven and a half minutes long—but it stays with you for days or even weeks after hearing it.
If you have some time today, I recommend finding a quiet spot and listening to it here. To get the full experience, close your eyes, and imagine that you are in the audience. And you will be moved too.