I am working through The Armor of God Bible Study by Priscilla Shirer. It is a really great study on the armor of God and the battle that rages around us. It teaches how to run defense against the enemy and how to take back ground that has been lost or surrendered. This study is changing so much about what I know about spiritual warfare, and my inheritance in Christ. The bulk of the study comes from the book of Ephesians and I highly suggest it.