Fighting the Demons
From the Holy Rule of St. Benedict:

CHAPTER I
an excerpt:

The second kind is that of Anchorites, or Hermits, that is, of those who, no longer in the first fervor of their conversion, but taught by long monastic practice and the help of many brethren, have already learned to fight against the devil; and going forth from the rank of their brethren well trained for single combat in the desert, they are able, with the help of God, to cope single-handed without the help of others, against the vices of the flesh and evil thoughts.


Special note:  Fr. Mauritius speaks of a book by Evagrius of Pontus, the link is below :
Evagrius Of Pontus: Talking Back: A Monastic Handbook for Combating Demons (Cistercian Studies)
Father Mauritius Wilde, OSB, Ph.D., did his philosophical, theological, and doctoral studies in Europe. He is the author of several books and directs retreats regularly. He serves as Prior at Sant’Anselmo in Rome.
For more, be sure to visit The Holy Rule of St. Benedict Rule with Fr. Mauritius Wilde O.S.B. Podcast Discerning Hearts page