I’m sorry that this will seem too “academic” and perhaps even “pedantic,” but it’s what I have to offer, right now.
There are two Greek words that are of importance this weekend (even though only one features in the Scriptures for Mass): dynamis and exousia: “power” and “authority.” The latter word has special meaning in this weekend’s Gospel excerpt. We need to see their inter-relationship.
Clearly, Jesus had the “power”—He exorcised demons and healed the sick. This was overt, observable by all, and without doubt. The real question was (and is) where the power came from: in other words, we need to know (as He was asked by the chief priests, scribes, and elders, after He cleansed the Temple) “By what authority are you doing these things?” Perhaps a clearer translation of this phrase and its use of exousia for us would be “What/Who gives you the right to do these things?” This is critical: the power is undeniable; the issue is its source.
Jesus had a tendency to play “fast and loose” with Sabbath prescriptions (“The Son of Man is lord even over the Sabbath”), and for observant Jews this was a serious problem. So: what if His “power” comes from the “authority” of Satan, for the purposes of leading people astray from fidelity to Torah and God? Jesus was accused of this, as we know, and the charge was not dismissive or mean-spirited; folks needed to know. Of course, Jesus’ reply to this charge is really brilliant (read Mark 3:20-27). He is effectively saying that even if this is the case, it’s still Good News for you—the realm of the prince of demons is experiencing civil war, and his realm will fall! “But if it is by the finger of God…” (Luke 11:20).
This is Jesus’ healing “authority,” but He also has explicitly teaching authority. In our context this means that He doesn’t bother to quote the precedents of previous rabbis in debating an issue—He declares on His own what is right and true (re-read Matthew 5:21-48, the so-called “Six Antitheses”), going so far as, if not correcting, at least expanding Torah. Who does He think He is—God??
That’s for us to answer. “By what authority” is just a re-wording of the central question of St Mark’s Gospel: “Who do you say that I am?” Remember—the answer to this question must be lived, not simply mouthed. Lent is coming—it will be the perfect time to reflect for ourselves our own personal, consequential response. Who do we say that He is? What difference does it make in our lives?