According to the Roman Catholic Church, what defines what “must” be believed? Obviously it goes beyond the credal statements. Is there a single authoritative source for what must be believed? Is there much disagreement among Catholic theologians and scholars about what must be believed?
I am somewhat chagrined to realize that after over 16 years of Catholic education, years of teaching Catholic Sunday School, a lot of reading, I can’t answer that question.
But I can’t think of a better place to ask it than right here. We have so many thoughtful scholars in this group, I have already learned so much here, been given so much to think about …
This Council picked up what had already been agreed in the preceding centuries about the Trinity: God is Father, Son and Holy Spirit (cf. Mtt 28:19), and God is ‘Almighty and Creator of all things visible and invisible’ and the Son ‘for our salvation came down, and became incarnate and was made man, and suffered, and arose again on the third day, and ascended into heaven, and will come to judge the living and the dead’. What this Creed added was that the Son is ‘the only-begotten, born of the Father, that is of the substance of the Father, God of God, light of light, true God of true God, born, not made, of one substance with the Father, by whom all things were made, which are in heaven and on earth’. It also laid down that it is incompatible with the Faith to say that ‘there was when he [the Son] was not,’ and, ‘Before he was born, he was not,’ or that he was out of non-existence, or of another substance or essence, or that he was changeable or alterable.
This produced the following Creed (popularly known as the ‘Nicene’ creed):
‘We believe in one God, Father omnipotent, maker of heaven and earth, and of all things visible and invisible. And in one Lord Jesus Christ, the only begotten Son of God, born of the Father before all ages, light of light, true God of true God, begotten not made, consubstantial with the Father, by whom all things were made, who for us humans and for our salvation came down and was made flesh by the Holy Spirit and of the Virgin Mary, and became man, and was crucified for us by Pontius Pilate, suffered, and was buried and arose again the third day, according to the Scripture, and ascended into heaven, and sits at the right hand of the Father, and is coming again with glory to judge the living and the dead; of whose kingdom there shall be no end. And in the Holy Spirit, the Lord, the giver of life, who proceeds from the Father, who together with the Father and Son is worshipped and glorified, who spoke through the prophets. In one holy, Catholic, and Apostolic Church. We confess one baptism for the remission of sins. We look for the resurrection of the dead, and the life of eternity to come.’
This Council produced the following Definition of the Creed: ‘We confess one and the same Son, our Lord Jesus Christ, the same perfect in human nature, truly God and the same with a rational soul and a body truly a human being, consubstantial with the Father according to divinity, and consubstantial with us according to human nature, like unto us in all things except sin, [cf. Heb. 4:15]; indeed born of the Father before the ages according to divine nature, but in the last days the same born of the virgin Mary, Mother of God according to human nature; for us and for our deliverance, one and the same Christ only begotten Son, our Lord, acknowledged in two natures, without mingling, without change, indivisibly, undividedly, the distinction of the natures nowhere removed on account of the union but rather the peculiarity of each nature being kept, and uniting in one person and substance, not divided or separated into two persons, but one and the same Son only begotten God Word, Lord Jesus Christ, just as from the beginning the prophets taught about Him and the Lord Jesus Himself taught us, and the creed of our fathers has handed down to us’.
This Council did not really pronounce any new dogma, but confirmed Chalcedon in a direction more explicitly close to the teaching of Cyril of Alexandria. It also more clearly affirmed the Consubstantial Trinity: ‘If anyone does not confess that (there is) one nature or substance of the Father and of the Son and of the Holy Spirit, and one power and one might, and that the Trinity is consubstantial, one Godhead being worshipped in three subsistences, or persons, let such a one be anathema. For there is one God and Father, from whom are all things, and one Lord Jesus Christ, through whom are all things, and one Holy Spirit, in whom are all things.’
This council overturned the previous banning of the use of icons, and argued that they were licit and to be honoured. ‘We, continuing in the regal path [i.e.e that of the empress Irene], and following the divinely inspired teaching of our Holy Fathers, and the tradition of the Catholic Church, for we know that this is of the Holy Spirit who certainly dwells in it, define in all certitude and diligence that as the figure of the honored and life-giving Cross, so the venerable and holy images, the ones from tinted materials and from marble as those from other material, must be suitably placed in the holy churches of God, both on sacred vessels and vestments, and on the walls and on the altars, at home and on the streets, namely such images of our Lord Jesus Christ, God and Savior, and of our undefiled lady, or holy Mother of God, and of the honorable angels, and, at the same time, of all the saints and of holy men’.