Why are you Downcast Oh my Soul?

A quote from John Piper's 'The misery of Job and the mercy of God' that has been of encouragement this afternoon. (I'm feeling a bit down)

"Sometimes the spark of faith is slight
And does not make the darkness bright.
But keep it lit and you will find:
Far better this than being blind.
One little flame when all is night
Proves there is such a thing as light.
Remember now the place and price
Where Jesus promised paradise.
One answered prayer when all is gone
Will give you hope to wait for dawn."