Authority can mean different things to different people. For example, some document or other may be authoritative for particular group even though it's not reliable. It's just that the group has accepted that document as authoritative for their group. And some documents are truthful and reliable but they are ignored, so they have no authority for that particular group.
D. A. CarsonSystematic theology will ask questions like "What are the attributes of God? What is sin? What does the cross achieve?" Biblical theology tends to ask questions such as "What is the theology of the prophecy of Isaiah? What do we learn from John's Gospel? How does the theme of the temple work itself out across the entire Bible?" Both approaches are legitimate; both are important. They are mutually complementary.
D. A. CarsonWe want to fan the flames of Christians for whom inerrancy and the authority of Scripture are not mere shibboleths, but part of her life beat, part of the beating heart of what makes them tick. They revere Scripture, not because Scripture becomes an idol, but because it discloses God who is especially come after us in salvation and redemption through the person of his son, his cross, his resurrection, the full sweep of the gospel.
D. A. Carson