All Christians are front-line soldiers in the battle between God and Satan, between good and evil. If you were tasked with writing a daily campaign report, how many victories would you have to your name?
Perhaps you don't know your adversary, or even worse, you don't even believe they truly exist.
J. Oswald Sanders presents a study of our adversary: who he is, what his objectives are, what strategies he employs, etc. It also includes a training manual that shows us how we can become victorious soldiers, filled with the power of Christ.