We need to remember that this doctrine of biblical authority is one of the teachings of the Christian faith. As such it calls for faith, i.e. a believing commitment on our part, an attitude continuos with that of our Lord himself and his apostles, and with the historic view of the churches. This helps us to keep the doctrine of Scripture in perspective. We do not wait for a moment-by-moment account of our Lord's thoughts, words and actions before we trust ourselves to his sinlessness and hence his fitness to act as our Saviour, nor for signed statements of impartial eye-witnesses before believing and rejoicing in his resurrections; so we need not demand the resolution of every possible question before trusting ourselves to the infallible truth of Scripture and submitting to its authority.
-- p. 59, Know the Truth by Bruce Milne