Generally speaking, temptations according to our Fathers are the bearers of every agitation and pain which occur in our lives. Sometimes they provoke sorrow, sometimes anxiety, at other times physical pain. As a doctor, God orders the appropriate medicine according to the source of the passion which has overcome the soul. “Where I to count them, they would outnumber the grains of the sand” (Psalm 139, 18). To some people God permits the onslaught of temptations to abolish sins which have already been committed; to others to prevent them from committing the sins which they were about to commit. Certainly there are also testing temptations. These occur to reveal the strength of the virtue and the holiness of the great athletes, like Job, in order to strengthen the Church. Unless there is a cause which will become a motive, the most evil demons cannot start a fight, from which the onslaught of the spiritual war is launched.
 
One basic source from which they usually direct the attack is the passions which reside in a man’s soul. These passions are the wicked habits, which he has created out of negligence or self-love. The evil demons are watching these passions and their demands which want satisfaction, and bring to the mind wicked thoughts and force man to agree to them. When they achieve this, they continue pressing the enslaved man to proceed with committing the deed which he almost cannot resist.
– ‘The Significance of Pain’