Sermon: David’s Polygraph; Psalm 26

Sermon reached by Patrick H. Wrisley, D.Min., October 3, 2021

Have you ever had to undergo a lie-detector test? A lie-detector, or a polygraph, is a machine that a person is connected to which measures perspiration and changes in heart rhythm and blood pressure. If you answer incorrectly, i.e., tell a lie, a little needle with ink goes up and down in a certain way on a piece of paper to highlight whether you have spoken the truth or not. Polygraphs have been challenged over the years for their inaccuracies even to the point they are not allowed in court cases anymore as definitive evidence. While growing up, though, I learned there are other forms of polygraphs that did not require putting a band around your chest to measure respiration and the like. The polygraph I had to deal with was a carbon unit about 5 feet 3 inches tall. This polygraph was called, “Mom.”

My mother could always tell when one of us kids was lying. Just like a regular polygraph, she could judge our respiration, heart rate, and our pupil dilation to know whether we were telling the truth or not.  She could just look at us and know if we weren’t telling the truth. She was good.   

One Halloween after my parents’ divorce when I was 11, my best friend, Michael Golson and I were going out together that night and get into some mischief. I dressed up like a soldier with a green beret and olive drab fatigue pants that had these huge pockets on both sides of the legs. The pants were very baggy on the sides. Earlier in the day, Mike and I went to Mr. Ezzard’s country store off Mt. Paron Road and bought a couple dozen eggs apiece.

As the cool Atlanta Halloween Eve began to show dusk, I went to my room and put on my costume.  To make it look truly authentic, I even took some of my mom’s mascara and rubbed it on my face like camouflage. Before leaving my room, I carefully loaded up my cargo pockets on both legs with the eggs I bought earlier.

Momma was in the kitchen, and I was walked through the room I said, “I’ll see you later mom! Mike and I are going trick or treating tonight!”  She waved and after a brief pause said, “Wait a minute honey, I want to kiss you good-bye.”  Even at 11 years old, I was able to look down physically on my mom. She looks up at me and says, “Have a good time, honey.” She reached up to kiss my cheek and then she bent over and started vigorously slapping up and down my pants’ legs. She stood up again and looked at me and said, “I can’t stop what you are going to get into tonight, but I know I can trust you, right?” Nodding my head up and down I simply said, “Yes, ma’am” whereupon the pushed me out the door and locked it as the egg yolks were running down my legs that cool night. I don’t know how she did it, but she was an incredible, living polygraph machine.

Sometimes polygraphs are machines and sometimes they are a feisty 5’3” divorced women. And as we will hear today in our lesson, David gives us a polygraph to use to measure our honesty with God as well.  Turn in your Bible to Psalm 26, a Psalm of King David. Hear the Word of the Lord!

  Psalm 26

1 Vindicate me, O Lord,
    for I have walked in my integrity,
    and I have trusted in the Lord without wavering.
Prove me, O Lord, and try me;
    test my heart and mind.
For your steadfast love is before my eyes,
    and I walk in faithfulness to you.[a]

I do not sit with the worthless,
    nor do I consort with hypocrites;
I hate the company of evildoers,
    and will not sit with the wicked.

I wash my hands in innocence,
    and go around your altar, O Lord,
singing aloud a song of thanksgiving,
    and telling all your wondrous deeds.

O Lord, I love the house in which you dwell,
    and the place where your glory abides.
Do not sweep me away with sinners,
    nor my life with the bloodthirsty,
10 those in whose hands are evil devices,
    and whose right hands are full of bribes.

11 But as for me, I walk in my integrity;
    redeem me, and be gracious to me.
12 My foot stands on level ground;
    in the great congregation I will bless the Lord.[1]

So, let’s unpack this Psalm of David and see how it’s an ancient polygraph. The first thing we notice as we look at this Psalm is that David is making some very impressive comments about himself in his hymn to God. I picked up at least a dozen self-ingratiating remarks David has written down about himself.

  • He lives with integrity and has literally never slipped up in his trust in God.
  • He’s so confident in his “faith walk” he uses legal language as though he were talking to a court judge demanding the judge, i.e., God, scrutinize his life, check out the evidence of his righteousness, and tells God in effect, “Prove me wrong!”.
  • He brags about directing his life in love as he walks in faithfulness.
  • David declares that he doesn’t hang out with liars and is not a hypocrite.
  • He brags to God that he detests those people who are injurious of others and never affiliates with immoral behaving people.
  • He tells God that he is ritualistically pure and can come into the very presence of God at the altar.
  • David reminds God that he is an enthusiastic worshipper and worships in the right way.
  • He sings songs telling others how much God has blessed him and declares to all who will listen all the great things God has done.
  • He reminds God how much he loves the Tabernacle where God lives and then asks the Lord for special blessings because, well, David is a such a good, righteous guy that he deserves it!

Who couldn’t love a guy like that!? He sounds like one of those prosperity preachers we get on late-night TV with the big hair and slick looking Armani suits. David: What a guy! His prayer is so full of himself! David paints himself in this Psalm as the Uber-God-follower in that he does everything right in the eyes of the Lord. Oh, if only you and I could live a life like David’s!  If only we could walk with integrity, justice and righteousness like David does. If only our lives revolved around joyfully worshipping in the house where God abides and sing songs of all God has done for us! If only we could be like David, the man after God’s own heart!

But now, we pause and take a breath. It’s important that we need to remind ourselves that David himself didn’t live the life he is telling God he lives. His conversation with God stretches the truth just a wee bit. Lest we forget, David who wrote Psalm 26 is the same David who wrote Psalm 51 which is a tragic prayer of confession for the messed-up life he has lived. Psalm 51 reminds us David’s great moral and ethical failures with the whole Bathsheba and Uriah stories. In 2 Samuel 14, David showed laziness when other kings went to battle. David lusted, committed adultery, lied, gathered accomplices to enter the lie and conspiracy he was weaving, and set up the murder of his neighbor in Jerusalem. This is the David we meet in the scriptures!  David was far from perfect! So which Psalm is the right one?  Is David the man of Psalm 26 or is David the man who acknowledges his treachery and sin of Psalm 51? The reality is, he’s both.

David knew he was, as I remind us often, both a saint as well as a sinner. He knew he was chosen by God as well as a broken human being who needed God’s love and protection. Psalm 26 is the Psalm that describes the man David strives to be. He writes down a hymn of what a life with God should be like for all of us. It’s a psalm you and I can use as a centuries-old polygraph holding us accountable to what a dedicated follower of Jesus should look like. Each verse in the Psalm 26 is a measure for our truthfulness in how well we are walking, living, loving, and being like Jesus.

This morning I invite you to keep your Bible open to Psalm 26 and use it to reflect upon your life. Simply ask yourself, “Am I?” or “Do I?” before each verse. So, for example, as you look at verse one, pray, “Do I walk in my integrity and have trusted in the Lord with my whole heart?” Or take verse two and ask, “Am I able to have the Lord test and probe my inner heart and thoughts?  What will the Lord find?” You can do this with any of the 12 verses of the Psalm.  The deal is this, though: If you answer yes, then honestly reflect on how you have. If you answer no, then you must ask the Spirit to reveal how you can. In the Name of the Father, Son, and Holy Spirit. So, be it.

© 2021 October 3, Patrick H. Wrisley, Pastor, First Presbyterian Church, 401 SE 15th Avenue, Fort Lauderdale, FL. 33301.  Sermon manuscripts are available for the edification of members and friends of First Presbyterian Church, Fort Lauderdale, Florida and may not be altered, re-purposed, published or preached without permission. All rights reserved.


1 New Revised Standard Version (NRSV). New Revised Standard Version Bible, copyright © 1989 the Division of Christian Education of the National Council of the Churches of Christ in the United States of America. Used by permission. All rights reserved.

About patrick h wrisley

A Mainline Presbyterian Orthodox Evangelical Socially Minded Prophetic Mystic Preacher sharing the Winsome Story of Christ as I try to muddle through as a husband, father, friend, head of staff, colleague, and disciple.
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