The Kyrie is an ancient prayer, attested by the fact that it remains in Greek even in Roman liturgy. It is based upon the biblical cry found twice in the mouth of blind men imploring Jesus’ help in Matthew 20:30-31, as well as similar pleas in Matthew 17 and Psalm 123. The Kyrie has endured in the penitential portions of the liturgy, often being sung ninefold (each line being sung thrice) or even in a set of forty (as in Byzantine liturgy to this day) early in the Communion service. Its appearance in the Daily Office has been consistent through the English and Canadian Prayer Books, though it was omitted in the American Prayer Books until now.
It is a simple prayer, its near-identical repetition making it both a challenge and an opportunity for devotion. The obvious challenge is how easy it is for the worshiper to utter the words as a parrot, without meaning or understanding. Such is the case with anything memorized. The opportunities, however, are manifold. This can prayed as a prayer of contrition – have mercy upon my sins. This can be prayed as a prayer of intercession – have mercy on my needs. The words “on us” (in the traditional form of the Kyrie) may be directed toward one’s family, one’s church, community, nation, or the entire world.
It also serves as a lead-in for the Lord’s Prayer. There, we have the boldness to address God as our Father, here, we address him as Lord and Christ. The Kyrie, thus, is directed primarily at God the Son, our only mediator and advocate who can bring us to the Father. In fact, a Trinitarian pattern of prayer can be inferred in teh sequence of Kyrie, Lord’s Prayer, and Suffrages: first we call upon the name of Jesus, then we address the Father, and then we pray in the Spirit with some God-breathed words of prayer.