Hieromartyr Irenaeus (c. AD 130-202) was bishop of Lugdunum in Gaul, which is now Lyon, France. A Greek from Smyrna in Asia Minor, he was brought up in a Christian family, rather than converting as an adult, and this may help explain his strong sense of Orthodoxy.
In his Against Heresies, he lays out several statements of the Faith, in language that would soon be echoed by the third- or fourth-century Apostles’ Creed. In Book 1, Chapter 10, he writes:
The Church is spread throughout the whole world, even to the ends of the earth. Yet everywhere she has received the same faith from the apostles and their disciples. She believes in one God, the Father Almighty, who made heaven, earth, the sea, and everything in them. She also believes in one Christ Jesus, the Son of God, who became man for our salvation. And she believes in the Holy Spirit, who spoke through the prophets.
Through the prophets, the Spirit proclaimed God’s plan: the coming of Christ, His birth from a virgin, His suffering, His resurrection from the dead, and His ascension into heaven in the flesh. The Spirit also proclaimed His future return from heaven in the glory of the Father. Then Christ will gather all things in one and raise up all flesh of the whole human race. At that time every knee will bow before Him—those in heaven, on earth, and under the earth—and every tongue will confess Him as Lord.
Then He will execute just judgment towards all. The the angels who transgressed and became apostates, together with the ungodly and wicked, will be sent into everlasting fire. But to the righteous and holy, to those who kept His commandments and persevered in His love, whether from the beginning of their course or after their repentance, He will grant immortality and everlasting glory.
Later, in Book 3, Chapter 4, Irenaeus sums up the faith of the church, again emphasizing that the church uniquely holds the deposit of the faith, “since the apostles, like a rich man [depositing his money] in a bank, lodged in her hands most copiously all things pertaining to the truth: so that every man, whosoever will, can draw from her the water of life.”
Many nations of those barbarians who believe in Christ agree with this teaching. Having salvation written in their hearts by the Spirit, without paper or ink, and carefully preserving the ancient tradition, they believe in one God, the Creator of heaven, earth, and everything in them, by means of Christ Jesus, the Son of God. Because of His great love for His creation, He willingly was born of the Virgin, uniting humanity to God in Himself. He suffered under Pontius Pilate, rose again from the dead, and was received up in glory. He will come again in glory as the Savior of the saved and the Judge of those who are judged. And He will send into eternal fire those who corrupt the truth and reject His Father and His coming.
These people believe this faith even without written documents. In terms of language, they are barbarians; but in doctrine, conduct, and way of life, they are very wise indeed because of their faith. They are pleasing to God, ordering their way in righteousness, chastity and wisdom.
In the third and final place where Irenaeus writes a creedal statement, his emphasis is on the creedal statement as being the judge of who belongs to the church and who does not (Book 4, Chapter 33):
He will also judge those who cause schisms. Such people are destitute of the love of God, seeking their own advantage instead of the unity of the Church. For small reasons, or for any reason that seems good to them, they tear apart and divide the great and glorious body of Christ, and as far as they are able, they destroy it. They speak about peace, yet they create war. They strain out a gnat, but swallow a camel. No reform they accomplish can outweigh the harm caused by their schism.
He will also judge all who are outside the truth, that is, outside the Church. But he himself is judged by no one. He has a full faith in one God Almighty, from whom are all things. He believes in the Son of God, Jesus Christ our Lord, through whom are all things, and in the divine dispensation by which the Son of God became man. And he believes firmly in the Spirit of God, who equips us with knowledge of the truth and reveals the dispensations of the Father and the Son, through which the Spirit dwells with every generation of men, according to the will of the Father.
