Here's a book you all should read, one time or another. I'm reading it for the second time right now and there is still soo much eye-opening stuff in it.
It has really helped me to understand that there is indeed a spiritual battle raging on around us. And the battle isn't between fat, naked little cherubs with harps, and demons dressed in red tights, with spade tails and tridents.
There is a serious battle going on that we are to be aware of and prepared for. "Put on the full armor of God...."
Anyway, I wish I could tell you more but you'll just have to read it. It is very similar to the Screwtape Letters written by C.S. Lewis.
Note: I don't exactly recommend it for younger kids....who are 11 and younger. But if you're a teenager or soon to be, I highly recommend it.