"Sometime in the middle of the night I woke up," writes Mike Brakken in Powers. "I couldn't breathe. I couldn't move. I couldn't even move my eyes. It felt like a weight of unimaginable strength was pressing down on me and paralyzing me. I was sure I was going to die.

"Even more terrifying, I felt a presence. I couldn't see anything, but I could feel palpable evil around me. I was overwhelmed and terrified, and it felt like there was nothing I could do. I don't even remember if I prayed."

For some, the term "spiritual warfare" conjures up images of horror movies and Hollywood demons. That is not how the Bible sees it; spiritual warfare is simply part of the Christian life. From the moment of salvation to the return of Christ, our lives are war, conflict and struggle.

Writing from a missionary's perspective, Brakken reminds us that temptation proceeds not only from our own hearts but also from the voice of a spiritual enemy. It is a war, but we don't have to go into it unprepared.