Book excerpt: We often think of demons appearing only in extravagant and extraordinary manifestations or working only through "bad" people. But the truth is more frightening than that. Most demonic activity takes place undetected, under the radar, and can even be hidden in our own prayer lives and in the churches where we attend Mass. Subtlety, illusion, and deceit are the preferred tactics of Satan's army of fallen angels, and they are waging an invisible battle for souls -- right now -- within and around us all. With St. Teresa of Avila's masterpiece The Interior Castle as his guide, bestselling author Dan Burke takes you on an illuminating journey through the seven levels of spiritual progress, explaining what God is accomplishing within your soul at each stage, as well as the finely tailored demonic strategies applied to throw you off your path. You'll learn how the devil is as active in your prayer life as you are, and how the saints were able to counter Satan as he adapted his schemes to correspond with where they were on their spiritual journeys. By discovering the myriad challenges St. Teresa faced and the remedies she employed to advance the spiritual progress of her soul, you'll know precisely what to expect as you progress in your current state to your final spiritual destination. You'll also learn: The marks of authentic contemplative encounter with God Why God uses dryness in prayer to advance the progress of our souls How to know if you're still in the "Purgative Way" How desolation can work for the good of the soul Why it's dangerous to assume that your decisions are correct if you feel at peace How to fight distraction in prayer The 11 ways to test the authenticity of charismatic gifts