Usage through the centuries, for example, is important. Doubtles Christians will continue to find books that are edifying and stimulating. But the closed canon points to a truth of permanent importance. God has acted to bring men salvation and he has not left himself without adequate witness to what he has done. The Bible is not a compendium of religious knowledge, a book in which we might expect to find an answer to all our religious questions.
Nothing can replace the authentic deposit of Christian truth.
Surely on none other than that of faithfulness to the Scripture. It is the Bible that gives the authentic Christian message. When the church can demonstrate that it is faithfully proclaiming that message it can claim to be on the right track. But the fact that they are edifying does not make them authoritative in the biblical sense. The Bible is unique.