Cyril of Jerusalem

How truly precious is the Holy Spirit, the good sovereign! Thus we receive baptism in the Father, in the Son and in the Holy Spirit! He fights against many demons who attack those who are still burdened by the body with beastly ferocity. But that demon whom so many are unable to bind with iron chains has often been conquered by the recitation of a single prayer, through the power of the Holy Spirit who lives within: the mere breath of the exorcist, like a fire, puts him to flight, and he disappears. God, therefore, has given us a mighty ally for the battle, a true protector—a great Teacher for the church, a great defender for each of us. We need not fear demons or the devil, because the one who fights for us is stronger. Let us open the door that he would come to meet us, "seeking those who are worthy of him" and desiring to give us his gifts.