by St. Irenaeus of Lyons
The holy and glorious, right-victorious Hieromartyr Irenaeus of Lyons (c. 130-202) was bishop of Lugdunum in Gaul, which is now Lyons, France. His writings were formative in the early development of Christian theology. He was a disciple of Polycarp of Smyrna, who himself was a disciple of the Apostle John the Theologian. His feast day is August 23.
This is an excerpt of his masterwork, Against Heresies, Book I.
1. The Church, though dispersed through our the whole world, even to the ends of the earth, has received from the apostles and their disciples this faith: [She believes] in one God, the Father Almighty, Maker of heaven, and earth, and the sea, and all things that are in them; and in one Christ Jesus, the Son of God, who became incarnate for our salvation; and in the Holy Spirit, who proclaimed through the prophets the dispensations of God, and the advents, and the birth from a virgin, and the passion, and the resurrection from the dead, and the ascension into heaven in the flesh of the beloved Christ Jesus, our Lord, and His [future] manifestation from heaven in the glory of the Father
“to gather all things in one,”
and to raise up anew all flesh of the whole human race, in order that to Christ Jesus, our Lord, and God, and Savior, and King, according to the will of the invisible Father,
“every knee should bow, of things in heaven, and things in earth, and things under the earth, and that every tongue should confess”
to Him, and that He should execute just judgment towards all; that He may send “spiritual wickednesses,” and the angels who transgressed and became apostates, together with the ungodly, and unrighteous, and wicked, and profane among men, into everlasting fire; but may, in the exercise of His grace, confer immortality on the righteous, and holy, and those who have kept His commandments, and have persevered in His love, some from the beginning [of their Christian course], and others from [the date of] their repentance, and may surround them with everlasting glory.
2. As I have already observed, the Church, having received this preaching and this faith, although scattered throughout the whole world, yet, as if occupying but one house, carefully preserves it. She also believes these points [of doctrine] just as if she had but one soul, and one and the same heart, and she proclaims them, and teaches them, and hands them down, with perfect harmony, as if she possessed only one mouth. For, although the languages of the world are dissimilar, yet the import of the tradition is one and the same.
For the Churches which have been planted in Germany do not believe or hand down anything different, nor do those in Spain, nor those in Gaul, nor those in the East, nor those in Egypt, nor those in Libya, nor those which have been established in the central regions of the world. But as the sun, that creature of God, is one and the same throughout the whole world, so also the preaching of the truth shines everywhere, and enlightens all men that are willing to come to a knowledge of the truth.
Nor will any one of the rulers in the Churches, however highly gifted he may be in point of eloquence, teach doctrines different from these (for no one is greater than the Master); nor, on the other hand, will he who is deficient in power of expression inflict injury on the tradition. For the faith being ever one and the same, neither does one who is able at great length to discourse regarding it, make any addition to it, nor does one, who can say but little diminish it.
3. It does not follow because men are endowed with greater and less degrees of intelligence, that they should therefore change the subject-matter [of the faith] itself, and should conceive of some other God besides Him who is the Framer, Maker, and Preserver of this universe, (as if He were not sufficient for them), or of another Christ, or another Only-begotten.
But the fact referred to simply implies this, that one may [more accurately than another] bring out the meaning of those things which have been spoken in parables, and accommodate them to the general scheme of the faith; and explain [with special clearness] the operation and dispensation of God connected with human salvation; and show that God manifested longsuffering in regard to the apostasy of the angels who transgressed, as also with respect to the disobedience of men; and set forth why it is that one and the same God has made some things temporal and some eternal, some heavenly and others earthly; and understand for what reason God, though invisible, manifested Himself to the prophets not under one form, but differently to different individuals; and show why it was that more covenants than one were given to mankind; and teach what was the special character of each of these covenants; and search out for what reason
“God hath concluded every man in unbelief, that He may have mercy upon all;”
and gratefully describe on what account the Word of God became flesh and suffered; and relate why the advent of the Son of God took place in these last times, that is, in the end, rather than in the beginning [of the world]; and unfold what is contained in the Scriptures concerning the end [itself], and things to come; and not be silent as to how it is that God has made the Gentiles, whose salvation was despaired of, fellow-heirs, and of the same body, and partakers with the saints; and discourse how it is that
“this mortal body shall put on immortality, and this corruptible shall put on incorruption; ”
and proclaim in what sense [God] says,
“`That is a people who was not a people; and she is beloved who was not beloved;”
and in what sense He says that “more are the children of her that was desolate, than of her who possessed a husband.” For in reference to these points, and others of a like nature, the apostle exclaims:
“Oh! the depth of the riches both of the wisdom and knowledge of God; how unsearchable are His judgments, and His ways past finding out!”
But [the superior skill spoken of] is not found in this, that any one should, beyond the Creator and Framer [of the world], conceive of the Enthymesis of an erring Aeon, their mother and his, and should thus proceed to such a pitch of blasphemy; nor does it consist in this, that he should again falsely imagine, as being above this [fancied being], a Pleroma at one time supposed to contain thirty, and at another time an innumerable tribe of Aeons, as these teachers who are destitute of truly divine wisdom maintain; while the Catholic Church possesses one and the same faith throughout the whole world, as we have already said.