St. John Chrysostom taught the faithful to use this effective spiritual weapon.
St. John Chrysostom was a Priest of the early Church recognized by the depth of preaching and spiritual writings, including a clear awareness of the spiritual battle that surrounds us in the world.
In his commentary on the Gospel of St. John, he taught the faithful a simple habit to prevent the presence of evil in a person.
Speaking of the fourth chapter of St John, Chrysostom exhorts his hearers to understand the Scriptures instead of simply possessing a beautiful copy of the sacred books:
I hear no one of you boast of knowing the contents of Scripture, but of having a copy written in gold letters. And what do I get, tell me, is that it? The Scriptures were not given to us only so that we have them in books, but that we may engrave them in the heart.
He sees in the assimilation of Scripture not only a necessity for the spiritual life, but a strong defense against the evil one.
I desire that, from these books, you should take the letters and the sense and take them to your understanding, so that it may be purified by receiving the meaning of what is written. For if the devil does not dare approach a house where a Gospel is present, much less any evil spirit or sinful nature will touch or enter into a soul which brings with it the sentiments contained therein. Sanctify your soul, sanctify your body, keeping always in your hearts and in your language the content and understanding of the Scriptures. While the vain discourse desecrates us and invites the demons, spiritual reading sanctifies us and opens us to the grace of the Spirit.
In summary: St. John Chrysostom believes that the soul that actually respects the words of Scripture and maintains its meaning always in the heart and lips will become practically impervious to any evil attack.
Chrysostom clearly understood the spiritual setting and knew how to defeat the powers of Satan. Their prayers are even used today in the rites of exorcism of the Orthodox Church:
May the Lord rebuke you, Satan! He who in glory ascended to heaven to the Father and sits at the right hand of majesty on the throne of glory. May the Lord rebuke you, devil!
The Holy Scriptures are a powerful defense against Satan, but they must reach the depths of our heart. As the author of the Letter to the Hebrews writes:
“For the word of God is living, efficacious, sharper than a two-edged sword, and reaches to the division of soul and body, of joints and marrow, and discerns the thoughts and intents of the heart” (Hebrews 4,12 )