This is a mystery of evil, that our gifts may be used for evil if we are not humble, not pure.
Some commentators have misunderstood this last posting on Satan. I am not writing for those who do not believe in him but for those who do, but blame him for the fact that there is so much evil in the world.
If no one cooperated with evil, Satan would have no power.
One of the problems is that people think that those who live in serious sin are possessed. No, this is not true. Oppression can come from Satan, and many of the saints experienced daily oppression, such as St. John Vianney. But, that is Satan on the outside causing pain, such as the inability to sleep because of a dog sitting next to one's bed barking, a demonic dog, as in the case of John Vianney.
Can people become possessed after years and years and years of serious sin? Yes, but the occult is still the first door to possession.
One cannot blame a life of choosing sin on possession. One can blame a life of sin on one's own choosing to sin.
Free will is given to all. Grace is given to all. And, we need to beg for grace. But, as much as one wants to blame Satan for one's lifestyle, one chooses, and the denial of free will one of the most common heresies here in Ireland and in England.