When Jesus began his teaching ministry in the synagogue of Capernaum, the people were amazed by the way he presented his message (see Mark 1:21-28). Unlike the scribes of that day, he spoke with authority.
In contrast with the scribes he spoke "as having authority." They were not lacking in assurance and self-confidence; they were unquestionably dogmatic and intolerant; but they spoke with borrowed authority. They were the professional students and interpreters of the Old Testament, but they only repeated what other men had said; they simply quoted "authorities." Jesus spoke with the power of personal conviction, he sounded the note of absolute certitude, his authority was that of divine insight. This difference in tone and power the hearers at once perceived; and measurably the same distinction between teachers can be recognized today. There is a loud and dogmatic assertion of borrowed truths and traditional beliefs, which fails to impress; while a quiet, modest statement of actual experience, of spiritual conviction and of personal vision, arrests and convicts.
Erdman, Charles R., The Gospel of Mark an Exposition, (Philadelphia, The Westminster Press, 1943), 34.
This certainly ought to cause each preacher of the Word to consider his own preaching. In other words, do you speak what you believe or just repeat what you have been told?