A Graduate School of Theology and Ministry

30th Sunday in Ordinary Time, Year C

October 23, 2022


Lectionary: 150

Sir 35:12-14, 16-18

Ps 34:2-3, 17-18, 19, 23

2 Tim 4:6-8, 16-18

Luke 18:9-14


Possible preaching themes:

  • Presumption, especially our own righteousness, runs the risk of blinding us to our need for God. Humbly acknowledging our need for God’s mercy opens us to growth in holiness.
  • In striving for holiness, we can get caught in a spirit of individualism, reducing faith to a personal reality. Instead of “running the race” of faith alone, we must support one another on our journey into God’s reign.


Possible scientific resources:




Homily outline combining both resources: 


About waves

  • For millennia, humans have stood on the water’s edge and observed the motion of waves. But what exactly is a wave?
    • Not an independent object, separate from but rather the motion of the water.
  • Similarly, sound is nothing more than waves propagating through air; 
    • a “sound wave” is the motion of air particles pushing together and relaxing, just like ocean waves crashing on the shore.
  • In the 19th century James Clarke Maxwell proved that light, too, was a wave.
    • An obvious question followed: a wave of what? What is being pushed and relaxed in order to create light waves?
    • It was presumed that a substance called “luminiferous ether” existed everywhere where light could travel:
      • It had to exist because waves travel through substances.
      • What were its properties?
      • How could it be discovered, proven to exist?
  • Albert A. Michelson and Edward W. Morley developed an extremely sensitive contraption, capable of proving the existence of the luminiferous ether:
    • the earth travels around the sun at a very fast speed; 
    • a light wave traveling in the same direction as the earth should be moving much more quickly than a light wave traveling in a different direction;
    • if they could show that to be true, they could prove the existence of the luminiferous ether.
  • The results of the experiment were confusing:
    • no change in speed was detected, regardless of the direction the light waves traveled.
  • Disappointed and deflated, Michelson and Morley published their results—or lack thereof—in a paper.
    • This presumed failure became one of the most significant, accidental discoveries of modern physics: light always moves at a constant speed
      • a fact which revolutionized physics,
      • became central to Einstein’s Theory of Special Relativity,
      • now called “the most famous ‘null’ result in physics.”
  • Presumption of the existence of ether and the disappointment of perceived failure, inhibited Michelson and Morley from realizing the significance of their discovery!


Gospel presumptions

  • Presumption in physics may delay discovery. Presumption in our faith lives is of greater concern.
  • The Pharisee in today’s Gospel is certain of his own goodness, even thankful for it:
    • he follows the religious law, unlike the others, even surpassing expectations
    • he’s proud of who he is, clearly better than others
    • he’s convinced of his own righteousness.
    • The tax collector has no reason for boasting:
    • he is a sinful man and knows it,
    • he humbly acknowledges his sin to God,
    • he recognizes his need for God’s mercy
    • The tax collector goes home justified


Unexpected grace

  • Our presumptions allow us to affirm that we are “good enough”:
    • we make it to Mass,
    • we are kind to others,
    • we are charitable and give to the poor,
    • we are better than a lot of people, so will surely get to heaven!
    • Yet, we are all flawed and sinful, needing to grow in multiple ways.
    • Recognizing that reality and our lack of progress can be disappointing—like Michelson and Morley searching for the ether.
    • But what looks to us like a “null” result is often God’s undiscovered mercy and grace.


Good news:

  • Jesus redeemed us from our sinfulness, revealing divine mercy and inviting us grow in holiness!
    • There is no spiritual contraption to measure whether or not we have crossed that special threshold of “good enough.”
    • Holiness is a lifelong relationship with the living God,
    • alternately admitting our fault
    • opening ourselves to new opportunities for receiving mercy
    • and reentering the race with Paul toward that crown of righteousness.
  • Mass can be a tax collector moment for us:
    • we acknowledge our sins and weakness
      • Lord, have mercy
      • Forgive us our trespasses
      • Lamb of God have mercy on us
      • Lord I am not worthy.
  • The Father’s response? 
    • “Take and eat; receive my Son, crucified for you; become like Him: holy, filled with grace.”
  • Presuming that we are good enough negatively impacts our individual and communal encounters with God’s mercy. 
    • We bow low, acknowledging our need for mercy.
    • But we do not do this alone
  • We are all in this race together
    • urging each other on through word and example in this kingdom marathon.
    • Just like Michelson and Morley needed the scientific community to open their eyes to their contribution
    • We too need faith communities to open our eyes to new possibilities in grace.
  • No matter what our effort, it is always outstripped by God’s lavish mercy and love,
    • revealed in God’s abiding Spirit, who sets the pace for us to run this holy race.



Liturgical: Ordinary Time
Topic: Physics

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