The Introit might be said to mark the actual beginning of the Service of the Word (the portion of the service built around the readings and the sermon). The word “Introit” is Latin for “entrance.” Prior to this point, the congregation has confessed their sins and received absolution. Historically, the pastor(s) would enter while the choir chanted the introit. In many churches still, the pastor moves toward the altar. As such, he indicates that he is going from representing the congregation to representing God to the people who have gathered to hear His word.
The Introit is the first of the variable parts of the service. It is generally taken from one of the Psalms. It reflects the theme or central thought for the service that day. Each Sunday in the church year has a specific Introit assigned to it which, together with the Collect of the Day, further develops the readings appointed for that day.
The Introit follows a particular form. It begins with the antiphon, usually one couplet. Then follows the psalm, usually an excerpt representative of an entire psalm. This is followed by the Gloria Patri. The antiphon may be repeated to finish the Introit.
Historically, the choir would chant the Introit antiphonally, that is, in two parts. Today, churches follow a variety of practices. In some, the choir still chants or sings the Introit. In others, the congregation chants or reads it. If the congregation chants it, they generally follow one of eight “melodies” to which each couplet is conformed. If the congregation speaks the Introit, they can read it in unison, read responsively between the two sides of the congregation, read responsively between the pastor and the congregation, or use one of a variety of other practices.
The Gloria Patri is included within the Introit to mark the Christian usage of the Psalter. We continue to use the Old Testament as it points to Jesus. The Gloria Patri, “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”, reminds us that these Psalm verses, written centuries before the Incarnation of Christ, still speak of Him and point to Him.
Among some Lutherans, the practice remains of bowing the head or the upper portion of the body “in due and lowly reverence” at the Gloria Patri and even at the name of Jesus throughout the service. Like making the sign of the cross, it is a practice which is not necessary, but is a good reminder to the individual of our relationship with our heavenly Father who has come to us and graciously forgives us our sins. It also helps encourage one to focus on what is being said, to some degree preventing the mind from wandering.