Long before Paul Tillich, men like Valentinus were engaging in theological accommodation and “methods of correlation.” David Dockery says of Valentinus, “His hermeneutical approach was more sophisticated than Marcion, beginning with a simple literal interpretation of the biblical passages and moving to a more esoteric instruction on ethical and spiritual truth.” In response, Irenaeus excoriates Valentinus, saying, “They gather their views from other sources than the Scriptures,” and then use their wicked schema to tie biblical phrases together to come up with another system of doctrine.
Irenaeus, on the other hand, from first to last is explicitly biblical. He outlines his method as one completely derived from the Bible, and he rejects Gnosticism on the basis that they corrupt the perfect word of God. Concerning the veracity of God’s word, he declares:
Our Lord Jesus Christ is the truth, and no lie is in Him. As also David says, prophesying His birth from a virgin, and the resurrection from the dead, “Truth has sprung out of the earth.” The apostles likewise, being disciples of the truth, are above all falsehood; for a lie has no fellowship with the truth, just as darkness has none with light.
Earlier Irenaeus affirms divine inspiration, biblical inerrancy, and the apostolic authority of the Scriptures, writing, “the Scriptures are indeed perfect, since they were spoken by the Word of God and His Spirit.” Congruently, Irenaeus holds to the unity and clarity of the Scriptures when he says, “the entire Scriptures, the prophets, and the Gospels, can be clearly, unambiguously, and harmoniously understood by all.” In short, though centuries before the Reformation and the publication of systematic treatments of doctrine, this second century divine is firmly evangelical. He argues for Scripture’s inspiration, inerrancy, authority, sufficiency, necessity, and clarity.
Though some have argued that Irenaeus’ regula fidei, which appealed to apostolic tradition to defend Scripture, led to “a precedent for setting up church traditions as being of equal authority with Scripture,” it can be equally discerned from his writings that the ultimate authority is the Bible itself. Contending against the Gnostics, whose fallacious doctrines had no historical warrant, he appealed to the church because the church is the “pillar and buttress of the truth” (1 Tim. 3:15). In reading Against Heresies, it does not appear that Irenaeus himself is elevating tradition to the level of authoritative Scripture, but rather that he exhorts people to flee to the church because it is the church that possesses the life-giving Word of God.
 The “method of correlation” was coined by Paul Tillich and encourages a dialetic approach to the Scripture where philosophy asks the question and the Bible supplies the answer. It is a twentieth century version of what the heretics have always done, comingle biblical truth with worldly philosophies (cf. Colossians 2:8). See Stanley Grenz and Roger Olson, Twentieth-Century Theology: God and the World in a Transitional Age (Downers Grove, IL: Intervarsity Press, 1992), 114-29.
 Dockery, Biblical Interpretation Then and Now: Contemporary Hermeneutics in the Light of the Early Church (Grand Rapids, MI: Baker Books, 1992), 60.
 Irenaeus employs one of his most colorful quotations to illustrate what these false teachers are doing. He writes, “Their manner of acting is just as if one, when a beautiful image of a king has been constructed by some skilful artist our of precious jewels, should then take this likeness of a man all to pieces, should re-arrange the gems, and so fit them together as to make them into the form of a dog or of a fox, and even that but poorly executed” (Irenaeus Adversus haereses 1.8.1).
 Irenaeus Adversus haereses 3.5.1.
Uniting inerrancy, inspiration, and authority together in one sentence, Irenaeus avows, “; but we, inasmuch as we are inferior to, and later in existence than the Word of God and His Spirit, are on that very account destiture of the knowledge of His mysteries” (Irenaeus Adversus haereses 2.28.2).
 Irenaeus Adversus haereses 2.27.2. He continues in 2.28.3, “all Scripture, which has been given to us God, shall be found by us perfectly consistent; and the parables shall harmonize with those passages which are perfectly plain; and those statements the meaning of which is clear, shall serve to explain the parables; and through the many diversified utterances [of Scripture] there shall be heard one harmonious melody in us, praising in hymns that God who created all things.”
 Michael Haykin, Defence of the Truth (Webster, NY: Evangelical Press, 2004), 39; see also David Dockery’s appraisal in Biblical Interpretation Then and Now, 71-73.
 See Irenaeus Adversus haereses 3.1-5 for a detailed section of his appeal to the “rule of faith” and the historical importance of the church to arbitrate right doctrine. Irenaeus Adversus haereses 5.20.1-2 gives an interpretive key for Irenaeus’ reasoning for appeals to the Church.