“Humor and laughter are the most powerful gifts in life,” said the Rev. Susan Sparks at the 10:45 a.m. Sunday morning worship service in the Amphitheater. “The congregation this morning is a visual reaffirmation of faith in the church, in that the numbers here this morning rival the numbers at a screening of ‘Harry Potter.’ ”

Her sermon title was “The Mulch Pile,” and the theme was letting go. The Scripture reading was Colossians 3:1-2, 8-14.

Sparks said she and her husband were traveling across the country, and to the west of Minneapolis they saw a billboard that had a picture of a casket “Minnesota Cremation Society — Think Outside the Box,” it read.

“That is what humor does — helps you think outside the box, see in fresh ways, and it builds community and bridges,” Sparks said.

Sparks quoted theologian Karl Barth, saying that humor is the closest thing we have to God’s grace.

“We can feel hope in our hearts,” she said, “because humor is there even if the world tries to beat it out.”

Sparks recently ended a three-month sabbatical. For the first month, she and her husband rode their Harleys around the country.

“That’s right, you have a biker chick and a comedian for a chaplain this week,” she said.

The second two months they spent in their cabin in Wisconsin — a place they visit regularly. It is near a town much like Garrison Keillor’s Lake Wobegon: 2,000 people and 17 Lutheran churches.

They have a ritual for their first morning — first, making “really bad coffee,” and then fishing for bluegills and other small fish and then cooking breakfast. During one visit, they threw the fish guts and egg shells into the trash after breakfast and went out to run errands. They had no air conditioning and the day was 93 degrees — “you can see where this is going,” Sparks said. When they got home, they were hit with the smell.

“I made a small gas mask out of wet paper towels and went in and got the trash and ran it out to the mulch pile,” Sparks said. “As you gardeners know, the trash turns into rich, dark soil that grows daylilies or tomatoes.”

In the Scripture reading, Paul tells the Colossians to get rid of their anger and malice and clothe themselves in a new self.

“Paul was writing in 60 A.D. and the danger he was writing about was gnosticism,” Sparks said. “He urged the Colossians to clothe themselves in the teaching of Christ. Paul is reaching out to us in the same way today and asking two questions — What trash are you carrying that needs to be put in the mulch? And what beautiful new thing can grow in its place?”

This is the arc for the week in her sermons: to look at what the trash is that needs to be put out on the mulch pile and, on Friday, to sum up what beautiful new thing might grow in its place.

“What trash are you carrying?” she asked. “Do you even know? Are you carrying anger, resentment, fear or self-doubt? Are you carrying racism, homophobia or other hatreds?”

Sparks said that sometimes when we are in denial, we don’t know that we are carrying trash or we have lived with generations of disregard for the problems. As an example, she said she threw her back out once and had to lie on the floor for almost a week. On the fourth day, after having read every newspaper and magazine in the house and binge-watched reruns of “Dr. Phil,” she was bored and her only view was under the furniture.

“I saw dust balls the size of ferrets, some leaky pens and paper and a strange orange square thing. It turned out to be a cheese appetizer from a cocktail party two years before,” she said. “I would not have known it was there unless I had been forced to look. You can’t take out the trash if you don’t know it is there.”

The second action in taking out the trash is letting go, and that is easier said than done. There are many things that we are used to but are useless to us.

“My father had a big old Buick boat of a car and he kept two spare tires, food, water, blankets and a foil space blanket in his trunk — in case there was a blizzard — to drive the 0.1 mile to from our house to his office in Charlotte, North Carolina,” she said.

We, she told the congregation, need to let go of privilege, apathy and ego as much as a foil blanket. She told the story of a man who fell off a cliff and was dangling from a tree, calling for help. A voice came from the heavens, saying, “Let go, my son, I have you.” The man thought for a moment and said, “Who else is up there?”

It can be hard to let go, but if we carry this trash too long it begins to define us. Ralph Waldo Emerson said what we worship, we become.

“I have a friend who calls it the 3Bs — believe, behave, become,” Sparks said. “What we believe drives our behavior and what we believe drives who we become.”

Sparks cited the first part of the Serenity Prayer, attributed to Reinhold Niebuhr, which reads: “God grant me the serenity to accept the things I cannot change; the courage to change the things I can; and wisdom to know the difference.”

She prefers the Senility Prayer: “God, Grant me the senility to forget the people I never liked anyway, the good fortune to run into the ones that I do, and the eyesight to tell the difference.”

“We have got to let go and throw things onto the mulch pile and in that moment, greater forces will take over,” Sparks said. “When we hand things over to a greater power, to Jesus Christ, it fades and changes into something beautiful and new.”

For instance, she said, we have to throw out our judgmentalism of others in order for mercy, empathy and forgiveness to grow.

“We judge people by the craziest things, like color, language or religion that have nothing to do with their being a child of God and our brother and sister,” she said.

She told a story from Jack Kornfield about two prisoners of war. The first one asked the second if he had forgiven their captors. The second one said no. “Then they still have you in prison,” the first one replied.

“We have more in common than we think and we have to start living like it,” Sparks said. “We have to begin with ourselves and forgive ourselves so we can forgive others. We have excuses for why we can’t do that, but if we have any lesson for today, it is that this body is our house, this heart is our house, this country is our house, this world is our house and it is our responsibility to take out the trash even if someone else brought it in.”

Poet Mary Oliver wrote, “Tell me, what is it you plan to do with your one wild and precious life?”

“If you care about this gift, don’t waste it on what weighs you down,” Sparks said. “Fling it on the mulch pile and clothe yourself in something beautiful and new.”