I believe, We believe: the Creeds & the Faith
Mankind's response to God's revelation of himself and of the way to eternal life should be one of faith. As the apostle writes in the eleventh chapter of the letter to the Hebrews, faith is substance of things hoped for and the evidence for things not seen. It is the essence of a Christian's response to the God of revelation, who uncovers himself for all people in both the Sacred Text of Scripture and in the Holy Tradition handed down for millennia by the apostles and their successors. Faith is the response of those who have encountered the one, living, and true God who became flesh and dwelt among his people at the Incarnation. Faith is a theological virtue: it is a habit that is ordered toward God. Faith is enabled by God's grace, and it is also the fruitful response to God's grace. Faith is a pre-condition for the normative means of salvation: one must have faith that God exists, that he can reveal himself, that he wants to reveal himself, that he cares enough about human individuals to bring about the means of their salvation, that he has the power to save, and that he will save. Faith is the bedrock upon which all biblical religion must be founded, in the sense that neither the Triune God nor the Way of Jesus can be known without it.
It is this faith that is encapsulated by the two great summaries of Christian belief known as the Apostles' and Nicene (Niceno-Constantinopolitan) Creeds. These two statements are used throughout the liturgy of the Church to transmit faithfully what it means to stand with the People of God and declare both, “I believe,” and “We believe.” The Apostles Creed is believed to be the original baptismal symbol of the Roman Church, with origins dating back at least to the Second Century. Within its structure are discernible earlier, less complex statements of faith, like that which Paul gives in the fifteenth chapter of the first letter to the Corinthians. There, the apostle states the kerygma in a concise but convincing way, and its affirmative statements and organizational structure can be detected in the Apostles Creed. Today in the Roman Rite, the Apostles Creed remains the baptismal symbol recited by catechumens and by the parents of infant candidates for baptism. It is recited by all the faithful at the Easter Vigil in token of the renewal of their baptismal promises. It is said by the dying as part of the last rites. It is said before the Rosary and the Divine Mercy Chaplet. It is recited by some who celebrate the Divine Office at the beginning of Lauds and Vespers. It permeates the Roman Rite in such a way that it could be said that somewhere throughout the world, it may be the case that there is always someone confessing the apostolic faith in the words of the Apostles Creed.
The other great Christian statement of faith, which the Catechism presents as the corporate confession of the whole Church, is the Niceno-Constantinopolitan Creed (“Nicene Creed”). The Nicene Creed is the result of two ecumenical councils, the first two held in the Church. The first version of the Creed, promulgated by the First Council of Nicea in 325, was much simpler than the second version, and it contained barely any reference to God the Holy Spirit. In 381, the First Council of Constantinople elaborated the Creed, fleshing out important details about the nature of the Incarnation and the person and role of the Holy Spirit, particularly with respect to the Church. This resulted in the present form of the Creed, which is confessed by all major branches of liturgical Christianity, including Catholics, Orthodox, Anglicans, and Lutherans.