(Editor's note: This begins a five-part series by Father Barratt on the creed to mark the Church's Year of Faith, which begins Oct. 11.)

As part of our celebration of the Year of Faith, we are going to explore the profession of faith, or the creed, that we say together at Mass on Sundays and important feasts in our liturgical calendar.

Our English word "creed" comes from "credo," the first word in the Latin version of the creed: literally, "I believe." The creed has been said by billions of Christians over many centuries and all over the world.

What is the creed, where did it come from and why is it so important to us?

It is good to remember that the creed we recite together is not just a statement about our belief in ideas or concepts, but a belief in something or someone personal. The creed is about our belief in God: one God, yet three persons - the Father, the Son and the Holy Spirit - and in God's life revealed to us and given to us personally.

We believe in and we love a personal God. So, when we say "I believe," we are not just offering some sort of opinion or making a statement about a subject like math, history or geography. We are making a choice, a decision and saying "yes" to the truth. In this sense, the creed is also about who we are, how we wish to live and what we hope for.

Sometimes, the language of the creed can seem difficult or puzzling. We need to recall that the creed was written some 1,600 years ago in a time and place that was both very different from ours and very similar.

Language and customs then could be quite different, yet the early Christians faced many issues and concerns and had hopes and joys that we would certainly recognize today. The creed can remind us our Christian faith is unchanging, yet it can grow and develop.

In the early Church, there were many statements of faith, often called symbols of faith. These were often recited by adults preparing for baptism. We still use these symbols today: for example, when we act as a godparent for an infant, when we renew our baptismal promises at times such as Easter or when a person is installed as a new parish leader. They usually take the form of a series of questions that summarize our faith. We respond to each question with a firm, "I do!"

However, there were a number of crises and challenges as the early Church struggled to find a language to articulate the Christian faith; so, at several Church councils between 325 CE and 451 CE, a creed was developed so that Christians everywhere could profess one, common faith.

This is the creed that we still use today. It takes its name, the "Nicene-Constantinople Creed," from two of those councils. (We also have a shorter Apostles' Creed that we are encouraged to use at Masses in certain seasons, or that can be said when we pray the Rosary.)

The creed is important to us because it is a summary of our faith and because it is a choice and a decision to believe and to live what we believe. Interestingly, the creed and the "Our Father" are both presented to catechumens in the Rite of Christian Initiation of Adults (RCIA) program, to symbolize two pillars of being a Christian: belief and prayer.

The RCIA instruction puts it well when it states that "the Church lovingly entrusts to [catechumens] the creed and the Lord's Prayer, the ancient texts that have always been regarded as expressing the heart of the Church's faith and prayer."

There is always a danger that we can say the creed (or indeed pray the Our Father) on autopilot, just rattling the words off without thinking about them or taking them to heart. Hopefully, our five-week exploration of the creed can help us to avoid this and, indeed, to think about the words, to savor them and so to deepen our faith.

Next week we will explore the first few phrases of the creed that speak of "the one God, the Father Almighty." In the meantime, do take time to begin your own reflection on the creed. Why not take a few minutes each day to explore a word or a phrase?

(Father Barratt is pastor of Annunciation parish in Ilion and Our Lady Queen of Apostles in Frankfort. He holds a doctorate in theology and was a professor at St. John's Seminary in England before coming to the U.S. in 2004.)