Our parish’s deacon preached this weekend. He pointed out the three instances of unworthiness as expressed in the readings, but he didn’t make it the centerpiece of his homily. Did you catch them in your celebration of the Word?
Isaiah:
For I am a man of unclean lips,
living among a people of unclean lips …
Paul:
For I am the least of the apostles,
not fit to be called an apostle …
Peter:
Depart from me, Lord, for I am a sinful man.
But I wonder: does a sense of unworthiness help shackle Christians to a limp and ineffective ministry? In light of a bleak near-future in Chicago lamented on this thread at PrayTell, do you think our struggle with worthiness hampers a greater effectiveness? This, especially when the situation of the modern world clearly points to solutions outside the box, if not beyond continuity with the past.
Sometimes, Christians wear their humility as a badge of pride. It can also be a ready weapon, to be wielded when someone else is in disagreement. (Who thinks you’re worthy to preach to me/them/priests/Pope Francis?)
Catholic Sensibility 
If something is worn as *a badge* of pride, it may be many things, but by definition the one thing it’s most definitely *not* is humility.
Modesty is different from humility. Humility, in essence, is seeing ourselves the way God sees us. It’s devoid of egoism. Modesty can be a tool of egoism – a way to manipulate others – and the manipulation can be defensive (to reduce the risk of harm to self) or aggressive.
I have seen more self-anointed prophets in ministry than I would have preferred. Some genuine ones, too. But a fair measure of reluctance, and avoidance of grandiosity (not the same thing as being visionary) and its fraternal twin, egoism (or at least egoism kept in a strong harness), is a good sign, not a bad one.
The point of the Paschal Mystery is that our unworthiness is not the last word on us. If we don’t accept the reality of our unworthiness, we can’t genuinely accept in joyful wonder the glorification that the Paschal Mystery offers us. There’s no eliding that.
PS: I recall the priest who browbeat a congregation into dropping the “not” from the Non Sum Dignus (he was a psychologist; I have seen more manipulative behavior from priest-psychologists than I care to remember).
Interestingly, our pastor preached this morning on those three instances of unworthiness, pointing out that there were three parts to each of them. The first was an encounter with God, a sense of a calling. The second was the resultant sense of unworthiness you mentioned. The third part was exemplified by Jesus’ words, “Do not be afraid..” By surrendering to grace and trusting in God we get beyond the unworthiness and don’t remain stuck in it.
“If anyone comes to me and does not hate even their own life — such a person cannot be my disciple.” – JESUS (Luke 14:26)
Passive-agressiveness on steroids.
I find it spooky and ironic the same individual had only a few chapters earlier granted near infinite power to those who follow such abjection:
“Behold, I give unto you power to tread on serpents…and over
all the power of the enemy: and nothing shall by any means hurt you.”
– Jesus (Luke 10:19-20)
Today we recognize Passive-aggressiveness to be a serious mental disorder. Ancient people cannot be blamed for not knowing better.