In the old Looney Tunes cartoons, when a character faced a dilemma, two little figures would pop up on each shoulder. So, Buggs Bunny, deciding what to do, would look on his right shoulder and see a rabbit that looked just like him, only with a white dressing gown over his body, a pair of wings protruding from his shoulder blades, and a halo above his head. Then, on the other side, there’d be a little bunny on the left shoulder, this time with a pitchfork in hand, a pointed tail, a long cloak, and horns sticking out of his head.

The shoulder angel and the shoulder devil. The angel told him what the right thing to do was, while the devil told him what the fun thing to do was.

In Judaism, these little inner voices have a name. We call them the yetzer hara and the yetzer hatov.

The yetzer hatov is the inclination to do good. It’s the voice inside us that tells us what we ought to do, even when it’s not easy. It’s the part of us that wants to be kind, humble, compassionate, generous, and forgiving.

The yetzer hara  is the inclination to do evil. It’s the part of us that feels envious, haughty, angry, selfish, and cruel. 

We all have the two within us, and there’s no point denying it. Some might like to pretend that they’re saintly through and through, but if they’re only lying to themselves. Because the force that’s responsible for kidding us that we’re better than we are? It’s that pesky yetzer hara.

There are those who want others to think they’re wholly wicked, too. Maybe because they’ve been told they’re bad so often they actually believe it. Or maybe because that hard exterior of callous selfishness gives them an armour against a world they don’t trust. But there’s plenty of good within them, and they know it’s there.

Not only do we have both a yetzer hara and a yetzer hatov, we need both. 

According to the midrash, at the time of creation God put inside us the good inclination and the evil one, and God said that both were very good.

Without the yetzer hatov, the good inclination, the voice of conscience, society would fall apart. We’d never be able to look after each other, trust each other, build community together. We need a sense of altruism to survive. 

And we need the yetzer hara too. We need that wicked inclination inside us.

The midrash says: “The evil inclination is a very good thing, for without it, nobody would ever build a house, get married, give birth, or do business.”

The yetzer hara is a motivator. Without a bit of fear, you can’t protect yourself. Without a bit of jealousy, you can’t achieve anything. Without a bit of lust, you won’t find a partner.

So God made us, deliberately, with all our qualities, including anger, apathy, cowardice, aggression, recklessness, and indecisiveness. We are supposed to have these qualities in order that we can be fully human. God looks at all of it – the whole person – and says: this is very good.

But, although we must have a wicked inclination, we can never give in to the yetzer hara. The yetzer hatov and the yetzer hara may always be in battle within our hearts, but it is our responsibility to make sure that the best within us wins. 

Have both, love both, but let your better self lead. Isn’t that why we come here on Yom Kippur at all: to become better human beings?

We must have a yetzer hara, but we cannot let it win. 

In the Talmud, Rav Asi says: when you first allow the yetzer hara to take hold, it’s as fine as the thread of a spider web, but if you grant it any quarter, it will grow as thick as a wagon rope.

Rava says: the yetzer hara might at first look like a traveller in the distance, then it feels like a guest at your door, but before you know it, the wicked inclination has taken over your whole house!

Don’t we already know that to be true? A little fear can feel a long way off, but anxiety can take control of the whole body. A little bitterness might feel like only a drop in the ocean, but in no time that can turn into all-consuming rage. 

So, what can we do with this yetzer hara that is both so necessary and so poisonous? 

Well, the wise King Solomon treated the yetzer hara as an enemy that he needed to befriend. He said, if you want to conquer an enemy, feed it when it’s hungry and, when it’s thirsty, give it something to drink. Then, says Solomon, it will be reconciled with you.

So, according to this reasoning, we need to understand the wicked inclination inside ourselves. I should be curious about my yetzer hara, and find out what it really needs. But only so that I can govern it, not so that it will conquer me.

If I’m feeling angry, that’s teaching me something about my boundaries, and I may need to enforce them. If I’m feeling afraid, that’s teaching me something about threats, and I should assess them. If I’m feeling jealous, that’s teaching me something about what I desire, so I can work out if it’s something worth pursuing. 

We are living in uncertain times. Many people feel poorer and more vulnerable. These are exactly the conditions in which the yetzer hara thrives. Sadly, we see it everywhere. 

Talking with leaders from other faiths, I know how much they feel this pain in their communities. I have more in common with Progressives of every other faith than I do with reactionaries who happen to be Jewish.

There are those in every religion who wish to take society back a hundred years; undo the rights of women; force gays and lesbians back into the closet; and cast trans people out from public life. There are those who believe that God loves only them; plays favourites; wants to see them take over the world; blesses every bomb they drop and cheers on every war.

Then, there are those of us, hanging on still in every religious movement, who know that God wants us to take the gentle path; find inroads towards peace; and live in harmony with nature. We, who uphold the rights of the vulnerable and seek justice for the oppressed.

Christian friends have shared their abject horror at seeing crucifixes paraded on white nationalist marches and fascists claiming Jesus as their own. Muslim colleagues describe their deep anger at how their faith is warped by chauvinists to control and destroy. Hindus express their anguish at how Hindutva extremists have ramped up ethnic tension.

And we Jews cannot claim any exemption from this problem. We know full well that there are Jews who use our history, our traditions and our religion, to carry out the most heinous abuses. We know that, in this climate of ignorance and fear, anyone can be seduced by the ugly rhetoric of hatred.

A few years ago, Rabbi Robyn Ashworth Steen wrote: 

“There are extremist voices among us, or perhaps even within us, that only speak in the language of revenge and of winners and losers. They would have us believe that there are sides, that some blood runs redder and thicker than others. Those voices whisper to us, luring us into their web. They would laugh at the idea that people are ultimately good.”

The extremist voice Rabbi Robyn named now feels increasingly loud. In all religions, we are facing a battle for our very soul.

Two years ago, an Oscar-winning film came out that portrayed this battle playing out in the Catholic Church. Based on a book by Robert Harris, Conclave depicts rival factions and personalities jostling for power after the death of a Pope. 

The conservative Catholics want a more robust, masculine, traditional Church to combat the onset of modernity. The liberals want to carry on the deceased Pope’s programme of modernisation and social justice.

The film compellingly portrays the conflict between the two tendencies in religions. At least, we liberals think it does. 

The climax of the film occurs when, all of a sudden, an Islamist terrorist sets off a bomb in the Vatican and the Cardinals have to be raced off to a safe room.

There, the conservative Cardinal reveals his true colours. He says it’s time for the Church to declare a holy war against those human animals.

At this point, a new Cardinal who hitherto had not spoken, gets up. He says, defiantly:

“My brother cardinal, with respect, what do you know about war? I carried out my ministry in the Congo, in Baghdad and Kabul. I’ve seen the lines of the dead and wounded, Christian and Muslim. When you say we have to fight, what is it you think we’re fighting? You think it’s those deluded men who’ve carried out these terrible acts today? The thing you’re fighting is here… inside each and every one of us, if we give in to hate now, if we speak of “sides” instead of speaking for every man and woman.”

This spiritual war, depicted for Catholics, is happening for us too. There is a battle for the Jewish soul, but it is not between the Orthodox and the Progressives, nor liberal and traditional, nor left and right. It is inside the heart of every Jew. 

This year, I have felt that spiritual battle in my own heart more intensely than any time I can remember. I do my best to be calm, lighthearted, generous, and joyous, because I know those are the traits God most needs me to bring into the world. But in my heart, I have often been feeling scared, defensive, angry, and confused.

Technological progress outpaced me when I was only a teenager, and now there are algorithms that threaten to destroy the planet. Corporations are plundering the reservoirs of drinkable water to fuel their machines, while churning out toxic gases into the atmosphere. 

I feel angry and afraid. Those feelings in themselves are neutral. But the yetzer hara latches onto them and says: not everyone will survive. Make sure you and yours do. Take and consume and stockpile. The yetzer hara says: the world is going to end anyway, so abandon your ideals, eat whatever you like, go wherever you like, forget about the future.

I can’t pretend I don’t have that voice inside me. So I need to understand it and bring it in line with the best within me. 

If I am scared about the natural world around me being destroyed, it is because I love life. I love this planet, and the English forests, and the Welsh mountains, and the Cornish cliffs, and the Scottish Islands. I adore the Thames and all its canals and tributaries. My fear is telling me what I want to protect. 

If I feel angry at corporate destruction, it is coming from a place of righteous indignation at how so few can destroy something so precious. 

The yetzer hara wants me to channel that fear into despair and that anger onto my fellow human beings. But the yetzer hatov is still there, insisting that it is never too late, that there is still hope, that we can still conserve our fragile ecosystem so future generations can swim in our rivers and drink from them.

Over the course of my lifetime, ethnic tensions and racial divisions have become increasingly pronounced and volatile. This year, antisemitism came for me, my colleagues, my congregants, and the people I care about in ways I never imagined it would.

I feel scared and confused. Those feelings, in themselves, are neutral. But the yetzer hara pounces upon them and says: see, the world hates us, it always has. To everyone else, we are the eternal scapegoat, and they’ll destroy us given half the chance. Pull up the fences around the synagogue, build bigger walls around Britain, pull up the drawbridge, keep the foreigners out of Europe, and stop any incursion on our way of life. 

It may surprise you to know I have these thoughts, because I certainly never let them impact how I treat others or make decisions in the synagogue. It takes an act of will, real spiritual struggle, to be hopeful and open and loving. It is a matter of determination. 

My goal isn’t to avoid feeling any anger, fear, or hatred. It’s to make sure I’m ruled by something greater.

I recognise that defensive voice as the yetzer hara. If I am scared about harm coming to Jews, I need to remember it’s because I love Jews and Judaism. I love our faith, our piety, our ever-evolving culture. I love, above all, our optimism and our desire to perfect the world. If I want to preserve Jewish life, I do it best by keeping us outward-looking, justice-oriented and inclusive.

If I feel worried that the society we have built in Britain where Jews thrive is at threat, it’s a reminder of how much I love multicultural social democracy. I want to live in our shared society, with all the other faiths and communities. It’s what’s best about London, and why many of us choose to live here. I can’t defend multiculturalism from inside an ethnic enclave. 

So the yetzer hatov says: get out there, build relationships, talk to people you disagree with, welcome newcomers and show them the advantages of tolerance, create cross-communal relationships, protect democracy. 

The yetzer hatov says: resist the voices of hate, whether they are directed at us, or at anyone else. Because it isn’t Muslims or immigrants that undermine our democracy. It’s the logic of racism and exclusion that threatens us. We protect Jews best by living in solidarity and partnership with our neighbours. 

Friends, we are gathering at a time of challenge in our country and in our world. The forces of nationalism and supremacism are gaining ground. Sometimes it feels like the Progressive voice will be lost entirely.

The countries of the world seem hellbent on a path to war and determined to build ever more hostile walls. We, who live in these countries, find ourselves increasingly pitted against one another in a climate of suspicion and aggression. 

But I am not giving up. 

However hopeless this world becomes, I will hold onto hope. However hateful others become, I will continue to love. And no matter what the forces of history may throw at us, I will continue to have faith.

Despite all our best efforts, we may not be able to control whether hatred and fear take over this world, this country, this society. But there is a place where I can refuse to grant hatred any quarter. 

It cannot take my soul. The forces of wickedness may succeed some places, but they will not win inside my heart.

There are many battles being fought in many places. Over territory, over resources, over truth. 

And there is a spiritual war taking place, inside every soul. Between love and hate. Between anger and compassion. Between welcome and fear. 

All those voices live within us, and they must all be heard. 

But only one can win. Only the voice of love. That is the only one God needs us to bring into the world.

Evil will not win inside my heart.

I will hold onto hope until the very end.

Gmar chatimah tovah. May we all be sealed in the Book of Life for good.