Discerning the Reasons for Believing in Visions

As confessors cannot see these effects [i.e. truth, majesty, efficacy], which perhaps the person to whom God has shown the vision is unable to explain, they are afraid of deception, as indeed they have good reason to be. Therefore caution is necessary and time should be allowed to see what effects follow. Day by day, the progress of the soul in humility and in the virtues should be watched: if the devil is concerned in the matter, he will soon show signs of himself and will be detected in a thousand lies. If the confessor is experienced and has received such favors himself, he will not take long in discovering the truth. In fact, he will know immediately, on being told of the vision, whether it is divine or comes from the imagination or the demon: more especially if he has received the gift of discerning spirits--then, if he is learned, he will understand the matter at once even though he has not personally experienced the like.