Be sober, be watchful. Your adversary the devil prowls around like a roaring lion, seeking someone to devour. Resist him, firm in your faith. -1 Peter 5:8–9
“‘Spiritual combat’ is another element of life which needs to be taught anew and proposed once more to all Christians today. It is a secret and interior art, an invisible struggle in which we engage every day against the temptations, the evil suggestions that the demon tries to plant in our hearts.” -Saint Pope John Paul II, May 25, 2002
“This generation, and many others, have been led to believe that the devil is a myth, a figure, an idea, the idea of evil… But the devil exists and we must fight against him.” -Pope Francis, Halloween 2014
How Demons Deceive Us
Although the powers of demons are infinitely weaker than the powers of God, they are still greater than those of humans, and their powers can fool us if we are not careful. For example, only God knows all things, including the future. God does not see time in a linear fashion as past, present, and future; rather, he sees all times at once. Everything that ever has been, is now, and ever will be, is present to him at once.
Demons, however, exist in time as we do, so they do not know the future. However, they are very intelligent and can make it appear that they know the future. One might think of them as extremely accurate weathermen: they don’t know the future, but they can make very good predictions.
Demons also have knowledge of human beings throughout history, and thereby know all human languages, including ancient ones. As we will see later, signs of demon possession include knowledge of things that the possessed individuals could not have known on their own, as well as the ability to speak languages that they have never heard.
Demons have the power to communicate with other demons and with human beings. However, being pure spirits, they communicate in a spiritual rather than a physical way.
Aquinas maintained that demons could affect our imagination. This ability does not differ greatly from our powers of communication. We communicate ideas to one another all the time through speaking and writing. Every time we turn on the television, read a newspaper or magazine, or search the Internet, we see advertisements. These are nothing more than someone trying to plant ideas or images in our imagination.
A particularly frightening ability of demons involves how well they know our personal habits. We have only to think of people whom we know very well. When they talk to us, we often know more of what is on their minds than they say, due to hints in their affect: we notice their tone of voice, facial expressions, and body language.
Because of demons’ greater intelligence, memory, and powers of observation, they are much better at interpreting human behavior and thought than we are. The demons can listen to us and observe us carefully, and may be able to see or hear subtle physical signs that show our emotions. Therefore, even though God alone knows all of our thoughts, demons can readily analyze what we are thinking and feeling, and make accurate predictions.
Demons can also deceive us through their ability to move physical objects. An example of telekinesis by a demon can be seen in the book of Job (1:13–19). In that biblical account, the devil caused lightning to kill the shepherds and sheep. In the same story, demons also caused a great wind that destroyed the house of Job’s children, thus killing them. The Gospels tell us that demons caused a herd of pigs to run off a cliff, fall into the lake, and drown (Mark 5:1–13).”
Love & Lord save us!!