The devil hates a pure soul, agile in humble reverence before the Lord. If the possessed person can go to confession, he or she should. This goes a very, very long way toward a successful exorcism if the person has been living a dissolute life.
Sin is not always the reason why Satan bothers someone. Sometimes it is extraordinary holiness. We need only think, for instance, of Saint Paul, Saint Jean-Marie Vianney, Saint Pio of Pietrelcina. Blessed Mary of Jesus Crucified, O.C.D., was bothered so much that she was a candidate for exorcism. Yikes! However, the more holy a person is, the more eager that person is to go to confession.
I would like to insist that sin is not always the reason why Satan bothers someone. It seems to me that the vast majority of exorcists have the mistaken notion that sin is the only reason for someone to be possessed. This is not the case. Not. Not. Not.
Along these lines, whatever you do, do not throw a guilt trip on someone, saying that they are possessed because they are in mortal sin. This would be the absolute worst thing you could do. This is like saying that someone who doesn’t speak in tongues must be in mortal sin, or that someone going through the dark night of the soul is having a tough time of it because of being in mortal sin. As Saint John of the Cross says, this is about the worst sin a priest can commit against a holy soul.
At any rate, sometimes this is not possible for the possessed person to go to confession. I remember a priest telling the story of a possessed woman who so very much wanted to go to confession, but could not. Every time she approached the confessional, she would be picked up by an unseen force and body slammed to the floor, obviously causing her intense pain and terrible distress that she could not participate in this great sacrament. I forget how the rest of the story went, but, if you ever run across a case like this, where there is a physical or moral impediment to oral confession, as can sometimes be the case in an emergency room, when someone is dying, etc., one can go ahead and give an absolution, instructing the person, of course, about being sorry for sin and having the intention of confessing in the normal manner as soon as this is possible. This, however, is rare. I’ve never myself come across such a case.
The best way to get anyone to go to confession is to go to confession yourself, frequently. Then, when you speak about going to confession, your words will have an inviting tone to them, for it will be clear that you yourself love this sacrament. If they have not been to confession in a long time, they will want to know the friendship you know with the Lord Jesus, who is so good and sokind.
And – Oh! – by the way: it is a very good idea not to hear the confessions yourself. There would be quite a bit of risk of knowing too much during the exorcism. Not good. You can’t use the information in any way at all. Get another priest to do this, a priest who is — how to say it — actually Catholic, who won’t excuse sin, but will gently forgive and encourage the penitents.
I have to really insist on this as well. It is the fashion these days to think that information gained in confession that is useful to the penitent, though not actually sin – can be used outside of confession for the sake of the penitent. That is not the case. This falls at least under indirect revelation of a confession if used publically. Nefas est, fathers! This also is condemned in Normae de gravioribus delictis (21 May 2010). To think otherwise – how to say it? — well, an analogy would be to say that only that which is meant to help us in our salvation is actually inspired in Sacred Scripture. Nope. Everything in Sacred Scripture is for our salvation and it is all inspired. Put it this way, if people weren’t going to confession, they would never open themselves up to you with details meant to give you a background to a situation they would otherwise not share with you. Respect, fathers, the vulnerability of people in confession! They will love you for it. Again, the best way is to get another priest not involved with the exorcisms to hear the confessions.
Of course, confession is very a very gentle suggestion, not a prerequisite!