Battling Unbelief is a great book, it's a more condensed version of another great book Future Grace. If you get the chance to read either of these, it would be a great encouragement to your soul. The DVD sessions are also a great compliment to these two works by John Piper, all of these resources are available at www.desiringgod.org
This video is an excerpt from the session entitled Don't Be Anxious. Great stuff, especially in these uncertain times.