In Jesus' high priestly prayer in John 17, He says: "And now, Father, glorify Me together with Yourself, with the glory which I had with You before the world was" (v. 5). Here Jesus alludes to a position He held before creation. It is a tacit claim to His participation in the eternal glory of God.
In the fourth century, the church faced a serious crisis with respect to the deity of Christ. The Arian heretics denied the deity of Christ, claiming that Jesus was a creature who was adopted into a special relationship with God. In their controversy with orthodox Christians, they used ribald and derogatory songs as a method of propaganda.
In response to the Arian attacks, the orthodox Christians composed their own songs, one of which was the Gloria Patri. Note the words of this well-known song:
Glory be to the Father, and to the Son, and to the Holy Ghost;
As it was in the beginning, is now, and ever shall be, world without end. Amen, amen.
In its inception, the Gloria Patri functioned as a type of fight song, a rallying cry for orthodox Christianity. That original function has been lost through the passing of time so that it is now used as a liturgical response. We no longer sense the extraordinary significance of ascribing glory to Christ.
Try using the Gloria Patri in this reading as a spiritual warfare song. Quote or sing it out loud.