This is the sermon I delivered at Temple Sinai in Cranston, Rhode Island, at the Kol Nidre service on October 1, 2025.
My family and I vacationed in the San Francisco Bay Area last year. On the second-to-last day of our trip, we spent an afternoon at Muir Woods National Monument just north of San Francisco. The park has some of the most famous old growth coast redwood trees in the world. The trees there plant their roots in the water of Redwood Creek and they soar above the foggy marsh to heights of 250 feet and more. The trees are breathtaking. They are even more astonishing when you consider that these trees began life, 500 to 1,200 years ago, as seeds no larger than an eighth of an inch.
As I admired those redwood trees, the question occurred to me, where did they come from? I don’t mean in a spiritual or figurative sense, but a very literal and material one. Some of the older coast redwood trees in Muir Woods weigh more than a million pounds. That’s not an exaggeration – one million pounds. All that mass had to come from somewhere. Where did all of that material come from?
Now, people have this idea about trees. We say, “trees grow out of the ground,” and that seems to make sense. We see that they have big roots burrowing down into the earth, so we imagine that this is where they get their substance – drawing it out of the ground through their roots.
But this is not actually how trees work. That becomes clear when you consider that there is no big empty hole beneath a tree from which it drew its material. If a million pounds of redwood were sucked out of the ground, there would have to be a huge void left behind.
A 17th century scientist from Brussels named Jan Baptist van Helmont discovered this when he conducted a simple experiment. Van Helmont grew a willow tree and he measured the weight of the soil it grew in, the weight of the tree itself, and the weight of the water he added to it. After five years, the tree had gained 164 pounds, but the weight of the soil was nearly the same as it had been when he started the experiment. From this he concluded that the tree’s weight did not come from the ground, but that it came entirely from water.
He was right that the tree does not consume the ground. But he was wrong about the water. Trees do not build their weight from water. So, if it’s not from the soil and it’s not from the water, where does a tree’s mass come from?
You might be thinking about the biology class you took in ninth or tenth grade and remember that there’s a process called photosynthesis that requires sunlight. Trees and all green plants need sunlight to grow. So, does the tree’s mass come from sunlight? Do trees directly convert energy into mass? No. Wrong again.
Let’s go back to that high school biology class and the process of photosynthesis. Green plants take in carbon dioxide from the atmosphere and water from the soil. They use the energy in sunlight to strip the carbon atom off of carbon dioxide (CO2) and recombine it with the oxygen and hydrogen from water (H2O) to turn into a sugar called glucose – (C6H12O6, for anyone who’s taking notes). That glucose becomes the building block for almost all of the plant’s mass – leaf, branch, stem and root. The plant also releases some oxygen back into the atmosphere as a helpful byproduct of this process.
When I say “helpful byproduct,” I mean “helpful” as in, “allows all animals on this planet to breathe.” That kind of helpful. It is also “helpful” in the sense that, by removing all of that carbon from the atmosphere, plants transform the earth into a place where all kinds of life can thrive and not a scorching hot rock with temperatures magnified by the greenhouse effect.
If you haven’t thanked a plant lately, now might be a good time.
The upshot of all of this is that the source of most of a tree’s mass – 95 percent of it – comes from the heaviest element that it takes in – carbon. And where does all of that carbon come from? You’re breathing it right now. It comes from the carbon dioxide, CO2, in the air. Plants turn air into solid material. The tens of thousands or hundreds of thousands of pounds in a tree – a million pounds in a large redwood – come from the carbon dioxide in the atmosphere. Trees are literally made out of thin air.
Now, I’m going to come back to those real, literal trees in a little while, but first I want to use trees as the foundation of a metaphor. There is a long tradition of trees being used as symbols in Judaism. In the book of Proverbs, the Torah is called “a tree of life to those who hold fast to it” (Proverbs 3:18). And the menorah – the seven-branched candelabra you see on either side of our ark behind me, the oldest symbol of Judaism – is actually modeled on the branches of a tree. You might also remember the burning bush – a small tree – from which God spoke to Moses. For thousands of years, Judaism has used trees as a symbol of life and of God’s presence.
Just as it is literally true – against all of our intuition – that trees grow out of the air, we can figuratively say that our lives are also made out of things as insubstantial as thin air. Think about it. What are the things you most value in your life, the things that give you a sense of meaning and purpose? Chances are, the first things you think of are not your house, your car, and your bank account. You probably have an intuitive sense that the real foundation of your life is in other things: friendship, trust, compassion, justice, faith, belief, and love.
In this sense, we are similar to the trees. We may look substantial and other people may see us first for our physical and material assets, but our lives are truly composed of things that are not things at all. Our existence is built out of thin air (metaphorically speaking).
What would your life be without the relationships you value the most? What would it be without your values and beliefs, hopes and aspirations? Most people would agree that life would be miserable and meaningless if life were just about our possessions and physical attributes. When the pursuit of the material becomes the central focus of a person’s life, it magnifies unhealthy attitudes: envy, greed, hardheartedness, and a belief that no amount of wealth can ever be enough.
When healthy, our lives are built upon values that cannot be weighed on a scale and that cannot be perceived under any microscope. Our lives are the cumulative assemblage of dreams, thoughts, emotions and wisps of hope.
Jewish tradition strongly endorses the idea that it is the non-material that really matters in our lives, and it warns us against worshipping “stuff” – things that can be seen, bought and sold. This is the essence of the second of the Ten Commandments – “You shall have no other gods besides Me. You shall not make for yourself a sculptured image, or any likeness of what is in the heavens above, or on the earth below, or in the waters under the earth.” (Exodus 20:3-4).
You thought that the second commandment was just about not worshipping idols? It means much more.
The second commandment is interpreted in Jewish tradition to mean that we should be on guard against the human tendency to think that our lives are based on things that are dug out of the ground, built by our hands, parked in our driveway, or saved in a bank. Our reverence should be reserved only for the God that cannot be represented in any physical form because God represents values that have no material substance.
The things that we should really revere in life are the divine attributes we experience in our most precious moments – the lift we feel in our soul as we watch our children grow up, the satisfaction and joy we experience when we help a friend in a difficult moment, the integrity we feel when we right a wrong, and the warmth in our soul when we embrace our beloved. That is what makes up the substance of our lives – and it comes to us as if out of the thin air.
And now, I want to come back to those very real and literal trees. As I said, one of the ingredients that allows trees to turn air into solid wood is sunshine. The energy that is absorbed by a tree’s leaves from the sun is used in the process of photosynthesis to turn carbon dioxide into glucose. The energy of that sunshine does not just disappear as the tree grows, or even after the tree dies. The energy is stored in the chemical bonds in every molecule of the tree.
As you surely know, if you add enough heat to a tree it will start a chain reaction that can toast your marshmallows…or burn down a forest. Human beings have used the stored energy in trees for hundreds of thousands of years – either as firewood or as coal. It was our main source of energy until the development of petroleum in the 19th century.
It is only in recent centuries, though, that we have used so much of the world’s trees that we face a worldwide crisis. In the last 300 years, roughly 35 percent of the earth’s forests have been lost to agriculture, urbanization, and logging. About half of those losses have occurred in just the last century. As we destroy our trees, we also damage the earth’s ability to remove carbon dioxide from the atmosphere to make the world habitable for human beings.
We can now return to the metaphor in which we recognize that our lives are sustained by ideas and values that are as insubstantial as the air from which trees derive their mass. Those ideas and values can also be burned to the ground. If we are particularly poor stewards of our lives, we can destroy the ideals and beliefs that sustain us. They are as inflammable as dried leaves. It is a painfully easy mistake to make.
When people lose sight of what really matters, and put their trust instead into wealth, status, fame or ego, they are metaphorically burning down their own house. Relationships are lost, values are sacrificed, and paranoia blossoms. I’m sure that you have seen this happen to people as I have seen it happen. Just like a tree, our lives can be destroyed by the fires of thoughtless greed, egotism, and tyranny.
This is also true of the values and beliefs that we share as a society. Justice only exists so long as people hold its rules and customs as sacred. When a system of justice is treated as a game to wield power over others or to punish enemies, it loses its meaning and part of the glue that holds society together is lost.
Equality only exists as long as people agree that every life is sacred and everyone deserves to be treated with dignity and respect. When we give in to the impulse to treat some as superior and others as inferior, we burn down the promise that all lives matter.
Hope – that word on the Rhode Island state flag and the word that is the translation of Israel’s national anthem – is made out of people’s shared ability to believe that things can be better than they are. Without hope, we lose the energy to repair what is broken in our lives and in our world. Without hope, we lose the ability to believe that our aspirations have any chance of ever being realized.
Justice, equality, hope, faith, integrity, and many other foundational values, too, will not be found as a literal ingredients in the bricks that build our homes, in the fuel that fills our gas tanks, or the food we put on the table. We might be tempted at times to say that we can’t live off of these insubstantial, high-minded ideals. In a real sense, though, they may be more important to living a meaningful life and to building a sustainable society than concrete, steel, oil or wheat. We, like the trees, are sustained by the insubstantial and our lives are built out of thin air.
On this Yom Kippur, take a look at your life and ask yourself what are the true foundations of your life. Consider the loving relationships that give you a real sense of meaning and fulfillment in life. If you are not paying enough attention to some of them, decide today to begin feeding them as they require and deserve. Think about your beliefs and values and pick out the three or four that really define who you are as a person. Recommit yourself to putting them at the center of your decisions and life choices. Make a list of the principles that you hold dear as the basis of a society you would like to live in. If you feel that they are fading, stand up to proclaim what you stand for.
All of these ideas, beliefs, relationships and experiences are fragile. Consider how easily they could disappear like smoke unless we make the conscious choice to tend and nurture them. Remember that our lives are not as permanent and fixed as we like to think they are. Our existence stands on a foundation of air.
On this Yom Kippur, let us remember the things that really matter to us that are not things at all. Let us dedicate ourselves to a year in which we place our highest values and dearest beliefs at the front of our lives, so that we will know that they are a tree of life when we hold fast to them.
G’mar chatimah tovah.
May you be sealed for a good year.
My family and I vacationed in the San Francisco Bay Area last year. On the second-to-last day of our trip, we spent an afternoon at Muir Woods National Monument just north of San Francisco. The park has some of the most famous old growth coast redwood trees in the world. The trees there plant their roots in the water of Redwood Creek and they soar above the foggy marsh to heights of 250 feet and more. The trees are breathtaking. They are even more astonishing when you consider that these trees began life, 500 to 1,200 years ago, as seeds no larger than an eighth of an inch.
As I admired those redwood trees, the question occurred to me, where did they come from? I don’t mean in a spiritual or figurative sense, but a very literal and material one. Some of the older coast redwood trees in Muir Woods weigh more than a million pounds. That’s not an exaggeration – one million pounds. All that mass had to come from somewhere. Where did all of that material come from?
Now, people have this idea about trees. We say, “trees grow out of the ground,” and that seems to make sense. We see that they have big roots burrowing down into the earth, so we imagine that this is where they get their substance – drawing it out of the ground through their roots.
But this is not actually how trees work. That becomes clear when you consider that there is no big empty hole beneath a tree from which it drew its material. If a million pounds of redwood were sucked out of the ground, there would have to be a huge void left behind.
A 17th century scientist from Brussels named Jan Baptist van Helmont discovered this when he conducted a simple experiment. Van Helmont grew a willow tree and he measured the weight of the soil it grew in, the weight of the tree itself, and the weight of the water he added to it. After five years, the tree had gained 164 pounds, but the weight of the soil was nearly the same as it had been when he started the experiment. From this he concluded that the tree’s weight did not come from the ground, but that it came entirely from water.
He was right that the tree does not consume the ground. But he was wrong about the water. Trees do not build their weight from water. So, if it’s not from the soil and it’s not from the water, where does a tree’s mass come from?
You might be thinking about the biology class you took in ninth or tenth grade and remember that there’s a process called photosynthesis that requires sunlight. Trees and all green plants need sunlight to grow. So, does the tree’s mass come from sunlight? Do trees directly convert energy into mass? No. Wrong again.
Let’s go back to that high school biology class and the process of photosynthesis. Green plants take in carbon dioxide from the atmosphere and water from the soil. They use the energy in sunlight to strip the carbon atom off of carbon dioxide (CO2) and recombine it with the oxygen and hydrogen from water (H2O) to turn into a sugar called glucose – (C6H12O6, for anyone who’s taking notes). That glucose becomes the building block for almost all of the plant’s mass – leaf, branch, stem and root. The plant also releases some oxygen back into the atmosphere as a helpful byproduct of this process.
When I say “helpful byproduct,” I mean “helpful” as in, “allows all animals on this planet to breathe.” That kind of helpful. It is also “helpful” in the sense that, by removing all of that carbon from the atmosphere, plants transform the earth into a place where all kinds of life can thrive and not a scorching hot rock with temperatures magnified by the greenhouse effect.
If you haven’t thanked a plant lately, now might be a good time.
The upshot of all of this is that the source of most of a tree’s mass – 95 percent of it – comes from the heaviest element that it takes in – carbon. And where does all of that carbon come from? You’re breathing it right now. It comes from the carbon dioxide, CO2, in the air. Plants turn air into solid material. The tens of thousands or hundreds of thousands of pounds in a tree – a million pounds in a large redwood – come from the carbon dioxide in the atmosphere. Trees are literally made out of thin air.
Now, I’m going to come back to those real, literal trees in a little while, but first I want to use trees as the foundation of a metaphor. There is a long tradition of trees being used as symbols in Judaism. In the book of Proverbs, the Torah is called “a tree of life to those who hold fast to it” (Proverbs 3:18). And the menorah – the seven-branched candelabra you see on either side of our ark behind me, the oldest symbol of Judaism – is actually modeled on the branches of a tree. You might also remember the burning bush – a small tree – from which God spoke to Moses. For thousands of years, Judaism has used trees as a symbol of life and of God’s presence.
Just as it is literally true – against all of our intuition – that trees grow out of the air, we can figuratively say that our lives are also made out of things as insubstantial as thin air. Think about it. What are the things you most value in your life, the things that give you a sense of meaning and purpose? Chances are, the first things you think of are not your house, your car, and your bank account. You probably have an intuitive sense that the real foundation of your life is in other things: friendship, trust, compassion, justice, faith, belief, and love.
In this sense, we are similar to the trees. We may look substantial and other people may see us first for our physical and material assets, but our lives are truly composed of things that are not things at all. Our existence is built out of thin air (metaphorically speaking).
What would your life be without the relationships you value the most? What would it be without your values and beliefs, hopes and aspirations? Most people would agree that life would be miserable and meaningless if life were just about our possessions and physical attributes. When the pursuit of the material becomes the central focus of a person’s life, it magnifies unhealthy attitudes: envy, greed, hardheartedness, and a belief that no amount of wealth can ever be enough.
When healthy, our lives are built upon values that cannot be weighed on a scale and that cannot be perceived under any microscope. Our lives are the cumulative assemblage of dreams, thoughts, emotions and wisps of hope.
Jewish tradition strongly endorses the idea that it is the non-material that really matters in our lives, and it warns us against worshipping “stuff” – things that can be seen, bought and sold. This is the essence of the second of the Ten Commandments – “You shall have no other gods besides Me. You shall not make for yourself a sculptured image, or any likeness of what is in the heavens above, or on the earth below, or in the waters under the earth.” (Exodus 20:3-4).
You thought that the second commandment was just about not worshipping idols? It means much more.
The second commandment is interpreted in Jewish tradition to mean that we should be on guard against the human tendency to think that our lives are based on things that are dug out of the ground, built by our hands, parked in our driveway, or saved in a bank. Our reverence should be reserved only for the God that cannot be represented in any physical form because God represents values that have no material substance.
The things that we should really revere in life are the divine attributes we experience in our most precious moments – the lift we feel in our soul as we watch our children grow up, the satisfaction and joy we experience when we help a friend in a difficult moment, the integrity we feel when we right a wrong, and the warmth in our soul when we embrace our beloved. That is what makes up the substance of our lives – and it comes to us as if out of the thin air.
And now, I want to come back to those very real and literal trees. As I said, one of the ingredients that allows trees to turn air into solid wood is sunshine. The energy that is absorbed by a tree’s leaves from the sun is used in the process of photosynthesis to turn carbon dioxide into glucose. The energy of that sunshine does not just disappear as the tree grows, or even after the tree dies. The energy is stored in the chemical bonds in every molecule of the tree.
As you surely know, if you add enough heat to a tree it will start a chain reaction that can toast your marshmallows…or burn down a forest. Human beings have used the stored energy in trees for hundreds of thousands of years – either as firewood or as coal. It was our main source of energy until the development of petroleum in the 19th century.
It is only in recent centuries, though, that we have used so much of the world’s trees that we face a worldwide crisis. In the last 300 years, roughly 35 percent of the earth’s forests have been lost to agriculture, urbanization, and logging. About half of those losses have occurred in just the last century. As we destroy our trees, we also damage the earth’s ability to remove carbon dioxide from the atmosphere to make the world habitable for human beings.
We can now return to the metaphor in which we recognize that our lives are sustained by ideas and values that are as insubstantial as the air from which trees derive their mass. Those ideas and values can also be burned to the ground. If we are particularly poor stewards of our lives, we can destroy the ideals and beliefs that sustain us. They are as inflammable as dried leaves. It is a painfully easy mistake to make.
When people lose sight of what really matters, and put their trust instead into wealth, status, fame or ego, they are metaphorically burning down their own house. Relationships are lost, values are sacrificed, and paranoia blossoms. I’m sure that you have seen this happen to people as I have seen it happen. Just like a tree, our lives can be destroyed by the fires of thoughtless greed, egotism, and tyranny.
This is also true of the values and beliefs that we share as a society. Justice only exists so long as people hold its rules and customs as sacred. When a system of justice is treated as a game to wield power over others or to punish enemies, it loses its meaning and part of the glue that holds society together is lost.
Equality only exists as long as people agree that every life is sacred and everyone deserves to be treated with dignity and respect. When we give in to the impulse to treat some as superior and others as inferior, we burn down the promise that all lives matter.
Hope – that word on the Rhode Island state flag and the word that is the translation of Israel’s national anthem – is made out of people’s shared ability to believe that things can be better than they are. Without hope, we lose the energy to repair what is broken in our lives and in our world. Without hope, we lose the ability to believe that our aspirations have any chance of ever being realized.
Justice, equality, hope, faith, integrity, and many other foundational values, too, will not be found as a literal ingredients in the bricks that build our homes, in the fuel that fills our gas tanks, or the food we put on the table. We might be tempted at times to say that we can’t live off of these insubstantial, high-minded ideals. In a real sense, though, they may be more important to living a meaningful life and to building a sustainable society than concrete, steel, oil or wheat. We, like the trees, are sustained by the insubstantial and our lives are built out of thin air.
On this Yom Kippur, take a look at your life and ask yourself what are the true foundations of your life. Consider the loving relationships that give you a real sense of meaning and fulfillment in life. If you are not paying enough attention to some of them, decide today to begin feeding them as they require and deserve. Think about your beliefs and values and pick out the three or four that really define who you are as a person. Recommit yourself to putting them at the center of your decisions and life choices. Make a list of the principles that you hold dear as the basis of a society you would like to live in. If you feel that they are fading, stand up to proclaim what you stand for.
All of these ideas, beliefs, relationships and experiences are fragile. Consider how easily they could disappear like smoke unless we make the conscious choice to tend and nurture them. Remember that our lives are not as permanent and fixed as we like to think they are. Our existence stands on a foundation of air.
On this Yom Kippur, let us remember the things that really matter to us that are not things at all. Let us dedicate ourselves to a year in which we place our highest values and dearest beliefs at the front of our lives, so that we will know that they are a tree of life when we hold fast to them.
G’mar chatimah tovah.
May you be sealed for a good year.
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