Bishop Olmsted on the Devil and Fr. John Vianney:
Fallen angels, also known as devils and evil spirits, try to hinder all of us in our pursuit of holiness. Their ordinary ploy is by means of temptations, which God allows so that we can make good use of our freedom in resisting them and thus growing to fuller maturity in Christ.
In addition to these ordinary ploys, demons resort to other extraordinary acts, on rare occasions, with the same intention of thwarting the plan of God and undercutting our filial trust in Him. These harassments can be of three kinds: infestations, obsessions and possessions.
With infestations, the devil makes use of noises, outcries, rattling, apparitions and other extraordinary outbursts of some sensible nature aimed at terrifying people, intending to undercut their confidence in God. He used these repeatedly on the Cure of Ars, sometimes to keep him from getting badly needed sleep, at other times to disturb his peace of mind and to try to shake his trust in God. All these were aimed at disrupting the effective ministry of this holy priest.Early on, Fr. Vianney became aware that these infestations were most outrageous just before an outstanding action of grace was about to occur through his priestly ministry, usually the conversion of a sinner. In fact, he remarked that the worst assaults of the devil happened when he was on the verge of “landing a big fish,”...
The Cure of Ars himself never suffered from demonic obsession or possession, but he dealt with them in others whom he served in his sacred ministry. With obsession, the devil goes beyond infestations and actually plays on the external senses of the body or influences a person’s memory or imagination. In cases of possession, which are even more rare than those of obsession, the devil actually uses the whole human organism, with the exception of the mind and will.The suffering that obsession and possession bring to a person is almost unimaginable. Moreover, to be freed of these satanic harassments, the Church’s sacred power from Christ is needed.