A very useful guide to discernment using St. Ignatius’ Spiritual Exercises by Br. Alexis Bugnolo: https://www.fromrome.info/2022/03/25/contra-spiritus-idolatriae-a-short-guide-to-the-discernment-of-spirits-2/
One of the most useful books that anyone can read to begin the spiritual life is the work by Saint Ignatius of Loyola on the Discernment of Spirits, which is called his book on Spiritual Exercises.
I say for beginners, because that is what the great Saint Theresa of Avila judged it to be, for beginners.
For beginners, because it deals with the first level of discernment: what is truly good and what is truly evil.
What is truly good is all that which leads you to take the side of Christ and live for Heaven, to arrive at Heaven and do all that is necessary to help others get there.
What is truly evil is all that which leads you to NOT take the side of Christ and NOT live for Heaven, to NOT arrive at Heaven and to do anything which impedes you or yourself to get there.
The second level of discernment is for those who have taken the side of Christ. As St. Ignatius says in his Spiritual Exercises, such persons can only be deceived by devils who APPEAR TO BE GOOD and angels of light, but which are experts in deceit.
So, on the second level, St Ignatius gives indirect rules for discernment, as to whether the propositions of a spirit to your soul leave you in a state of encouragement, light, zeal, or rather in a state of discouragement, darkness and sadness. He lays down this rule, that for those walking the way of virtue, a spirit from God adds to one’s encouragement, light, or zeal to serve Jesus Christ, and an evil spirit instead leaves one empty in proposing things too great, darker in understanding the will of God, or of less zeal in the things of Jesus Christ. Whereas, for those not on the path of virtue, a good spirit will cause one to lose zeal for serving creatures, see the lies in which one lives and turn aside from the pursuit of creatures, while an evil spirit will increase one’s obsession in the pursuit of creatures incite to the violation of more moral laws etc..
But, at the second level, this indirect rule of discernment of St Ignatius is often difficult, because it is indirect.
Or in other words, the rule of St Ignatius can confound souls, because it appears to fixate on interior states of the subject, how he feels and what he experiences, and thus in an age of sentimentalism and subjectivism is rarely practiced correctly, which is why the Society of Jesus in modern times has lost its path to God.
Rather, the direct rule of discernment at this second level is easier, namely, all which turns us away from loyalty to creatures and or towards loyalty to the service of God, is from a good spirit, and whatever does the opposite is from an evil spirit.
At this level it becomes extremely dangerous to use the imagination, because, just as the true God is the true reality of the spiritual world, so the soul which seeks him cannot find him in the world of imaginations. This is why St John of Cross counsels so strongly against reading novels for such souls. Today, we would say he counsels against watching movies, romances, television.
A soul dedicated to the service of God at this level has nothing to gain by such endeavors. And if tempted to know of them so as to counsel souls, he does better to read the critiques of zealous souls at a lower level than to watch them himself and put himself at risk of losing the grace of God.
At this second level, the key to right discernment is the criterion how to discern Spirits of Idolatry from Divine Spirits, that is evil angels from false ones. Because, as of yet, the evil angels will not manifest themselves, they will study the psychology of their victims and seek a weak point, where they will attempt to turn the soul away from God and towards seeking some satisfaction in creatures.
This is why at this level it becomes more important to fast (so as to break all attachments to food and drink inasmuch as this is inordinate and not necessary to do the will of God), to humble oneself at prayer and in daily life, especially in encounters with others (so as to break the chief vice which is pride), and to scrub one’s soul of attachments, many of which hold the soul back from serving God with a pure heart.
The lessen to be learned at this level is, God is My All, there is nothing I need which is not for His service, nothing which I desire other than to do His Will and remain faithful.
This self reflection is vital, because bad habits can lead to attachments and small deviations can allow the evil spirits to sway the soul back into sin. Here the study of the Divine Law, that is of the morality revealed by God, is vital, because through the smallest holes of ignorance about what is and what is not a sin, a soul can fall into great error, great evil and be transformed into a devil on earth, without recognizing it. So many clergy and religious have fallen from God on this score, and it is a rare soul who having strayed at this second level, returns to the Divine Service.
At the Third Level, a soul which has been faithful, whether for a short or a long time, will be tested to dedicate itself to the Divine Service through some greater work, whether it be by an inspiration to undertake a work of mercy or a work of justice.
These inspirations come most commonly from one’s guardian angel, so it is very important, in a state of grace, to make a promise to one’s Guardian Angel to heed his inspirations in all things, great and small, and to develop the knowledge of discerning when he is giving advice and following it IMMEDIATELY without any DOUBT or criticism. This takes a lot of practice and the soul often goes astray by following suggestions which are not from one’s guardian angel, but rather from the spirits of idolatry, that is of the world, the flesh or the demonic: and so the indirect rules of discernment of Saint Ignatius are a great help. We need to remember the lessons our Guardian Angel gives us and make a habit of doing readily the good works he inspires, because through them He will make known to us what God wants us to dedicate ourselves to and reveal to us our vocation, if we have one, whereby we are dedicated to God or his service.
Our Lady of the Annunciation is the example we need to follow in all our discernment. She showed Herself to be a master of discernment at the approach of the Archangel Gabriel, to know whether he was of God or not. She did not presume, she applied these rules. She also avoided the very common error of thinking that we need to wait in prayer to know what to do. Common knowledge is also a source of information about what good works to do, so as soon as She heard Elizabeth was in need, She packed up her things and headed out to help her. She was not a pietist, who believed prayer solved everything, and She was not a spiritualist, who believed that one only acts on the basis of inspirations had in prayer.
Let us pray for one another, that we be faithful to God, more faithful to God and live to be faithful to God in all we do. Amen. Ave Maria!