The evil spirit often disguises himself as an angel of light, and now and then tricks us by his illusions.
All of us must be ever alert for these tricks and should pay particular attention to learning how to recognize and overcome them.
—St. Vincent de Paul
You need great discrimination in order to distinguish between good and evil. So do not readily or lightly put your trust in appearances, but weigh things well, and after testing everything carefully cleave to what is good and reject what is evil. You must test and discriminate before you give credence to anything.
—St. Gregory of Sinai
However great may be the temptation, if we know how to use the weapon of prayer well we shall come off conquerors at last, for prayer is more powerful than all the devils. He who is attacked by the spirits of darkness needs only to apply himself vigorously to prayer, and he will beat them back with great success.
—St. Bernard of Clairvaux
The devil’s snare does not catch you unless you are already nibbling on the devil’s bait.
The soul possesses freedom; and though the Devil can make suggestions, he does not have the power to compel you against your will.
—St. Cyril of Jerusalem
The strategy of our adversary can be compared to the tactics of a commander intent upon seizing and plundering a position he desires. The leader of an army will encamp, explore the fortifications and defenses of the fortress, and attack at the weakest point. In the same way, the adversary of our human nature examines from every side all our virtues, theological, cardinal, and moral. Wherever he discovers the defenses of eternal salvation to be the weakest and most lacking, there he attacks and tries to take us by storm.
—St. Ignatius of Loyola
Let the enemy rage at the gate, let him knock, let him push, let him cry, let him howl, let him do worse; we know for certain that he cannot enter except by the door of our consent.
—St. Francis de Sales