After the sermon comes one of the three creeds. Creed is a term derived from the Latin for "I believe." So it is no surprise that the two most common creeds we use begin with "I believe..." These are the Apostles' Creed and the Nicene Creed. The third and least used of the three creeds is the Athanasian Creed.
In some congregations, the Nicene Creed is used on Sundays when the Lord's Supper is celebrated. The Apostles' Creed is used on Sundays when the Lord's Supper is not celebrated. And the Athanasian Creed is used for Trinity Sunday (the Sunday after Pentecost).
A somewhat recent movement to celebrate the Lord's Supper every Sunday has made the above a bit obsolete. Some congregations have adapted by simply alternating every other week between the Apostles' and Nicene Creed. Others use the Nicene Creed for the festival portion of the year (from Advent to Pentecost) and the Apostles' Creed for the Sundays after Pentecost.
The Nicene Creed was formed over the course of more than 50 years. Beginning in 325 at the ecumenical Council of Nicea, the church sought to articulate a confession to provide clarity against heresies that had arisen. The Creed wasn't completed until 381 at the Council of Constantinople.
The Apostles' Creed is steeped in a bit more mystery. It was long held that each of the 12 Apostles constructed one line of this confession and it was inspired by the Holy Spirit. From what I can tell, the Apostles' Creed began as part of the baptism rite in one corner of the early church. It was morphed and edited along the way. Its earliest construction (we'll call it a rough draft) was probably in the second century, but its current form wasn't settled upon until the eighth century.
Much like the Nicene Creed, the Athanasian Creed is aimed at articulating the faith in the face of heresies. The main concern in this case was the Trinity. The Father and the Son and the Holy Spirit are not parts or modes of the same God. All three persons are God. They are distinct from one another, yet united.
Within the worship service, the Creed stands as a moment of unity. Together the congregation confesses their faith in this Triune God. Christians throughout the world, in dozens of countries and thousands of languages confess their faith each week in one of these creeds. Despite denominational division, the Creed anchors us to unity. After all, it is in the Nicene Creed that we confess we believe in "one, holy, Christian/catholic, and Apostolic church." One. Not thousands. One.
To me, the Creed is a moment to reflect upon one of my favorite moments in Scripture. In Mark 9, when a man brings his demon-possessed child to Jesus, eventually this man confesses, "I believe! Help my unbelief."
I believe each line of each of these creeds. I ascent to them with my mind, my heart, my soul. But I don't always live like I believe. Oftentimes I live in disbelief, in unbelief, even in anti-belief.
Sometimes I act as if God's creation didn't matter. Sometimes I act as if Jesus' incarnation, death, resurrection, ascension, and return were nothing more than monotone facts of history, rather than the most important events to ever occur in the galaxy. Sometimes I act as if the Holy Spirit were nothing, and I seek to take credit for all of the ideas the Holy Spirit has given me.
The Creed is a time to say "Jesus is Lord," even if it is spoken in monotone. It is a time to remember that God is God, and I am not.