They are useful for God's purposes. The relevance of Scriptures demands we make intelligent and intelligible applications. This is possible based on three convictions. First, the biblical text is an inspired text which is powerful and useful. This high view of the biblical text, which is unlike any other text, unique in origin, nature, authority, and authorship, is indispensable to authentic missions.
Nothing undermines Christian missions more than skepticism about Scripture.
All Scripture is God-breathed. This gives the Bible authority. Second, the biblical text is an open text by which I mean the biblical text can be understood. God can speak so he can be understood. This text is useful for equipping.