It’s not enough to appeal to the Bible, as F. F. Bruce writes that St Irenaeus believed.
Heretics might appeal to the text of scripture, but their interpretation was vitiated because it did not accord with the rule of faith — the summary of Christian teaching handed down in the apostolic tradition. [Canon of Scripture, 172 n. 8]
This is consistent with what the Catechism says:
Read the Scripture within “the living Tradition of the whole Church”. According to a saying of the Fathers, Sacred Scripture is written principally in the Church’s heart rather than in documents and records, for the Church carries in her Tradition the living memorial of God’s Word, and it is the Holy Spirit who gives her the spiritual interpretation of the Scripture (“… according to the spiritual meaning which the Spirit grants to the Church”). [§113]
Like any document the Bible must be interpreted. When we interpret it, we do so according to some hermeneutical tradition or other. The Church teaches what St Irenaeus affirmed more than eighteen centuries ago: that our interpretation of the Bible must conform to the Faith. Gnostic appeals to the Bible were valueless precisely because they ignored the Faith, preferring their own errors. Those who interpret Scripture without listening to the Church commit the same error.