In previous Bible readings from Exodus, the outsider, Jethro, warns Moses that he is doing too much for one mere mortal, and advises him to choose assistants to help him guide the Children of Israel to the Promised Land (Exodus 18: 17-26).

Sometimes it takes an outsider to point out what is not obvious to your own tiny cult, sect or tribe, especially when a whole people is being established through trial and error from a rag-tag of ex-slaves.

The greatness of Moses is not that he is perfect, but that he listens to his father-in-law, who is deemed to have given him good advice. This has led to the Jewish saying that 'two heads are better than one'.

This week's prophetic reading, parallel to the Exodus story of the golden calf, tells the story of Elijah.

At that time of Jewish history, King Ahab and Queen Jezebel ruled over the Northern Kingdom of Israel and made a habit of murdering prophets, while filling their households with the false prophets of their idols.

Ahab's nemesis was Elijah, who braved threats of death to carry the word of G-d to the people. The climax was a momentous confrontation on Mount Carmel, where Elijah challenged the royal prophets of Baal, the god of storms, to a test that would establish for the children of Israel who was the fraud and who was the real thing ( I Kings 18:20).

When I lived on Mount Carmel a few years ago, the weather was nothing like what we experience here in the UK. Thunder and lightning appeared as gods; through unpredictable storms, all means of communication were destroyed for weeks on end, and on one occasion a lightening flash pierced the window and destroyed the computer, phone and TV in one go, as well as the entire lighting system.

It was hard in those days, at the end of the Second Lebanon War, not to feel that G-d Himself was against you, especially when taking part in a performance of Mendelssohn's oratorio Elijah at the very top of Mount Carmel, and reaching the verses of Psalm 121:

'I lift up my eyes to the hills: from where does my help come.... The Lord ... watches over Israel ... He slumbers not nor sleeps'.

At this point in the proceedings, which took place right at the top of Mount Carmel at the end of the war, in which Haifan citizens were murdered by rockets and a third of the city had had to be evacuated, the lights would inevitably go out and a palpable darkness ensued.

It was hard not to compare the situation to the original blackness experienced by Pharaoh's Egyptians themselves, as one of the 10 plagues. Undaunted, and guided by my fingers, I would carry on accompanying the choir, but surely there was a message in all this weather?

No wonder our ancestors regarded the elements as gods in need of placating.

So how easy it is when things go wrong to mistake the appearances of things as the real G-d of the Jewish people, otherwise known as Hashem (the Name).

What the children of Israel experienced at the time of Elijah was a quite understandable doubt, fomented by their royal leaders and the religious establishment represented by the false gods. But 'how long will you skip between two stools'? Elijah asks. 'Make up your mind: come to a decision.'

The word for 'skip' in Hebrew is the same as the word for 'Pesach', which designates the uplift we experience at the advent of the major Jewish freedom festival which retells the story of our journey from slavery. At this time, the children of Israel experience the springtime of their lives as they looked forward to their future free of bondage.

If only things were so simple.

Think of all the ways we express our reluctance to act in a difficult situation. We talk about 'sitting on the fence', 'leaving it all to the experts'. We then get a little more menacing: 'fools rush in where angels fear to tread'. And then two more that (being the child of Polish immigrants) I never learned as a child: 'when in doubt do nowt', and 'never trouble trouble until trouble troubles you'.

In other words, doing nothing in a difficult situation is mostly regarded positively and not as a decision in itself – the decision to act as a coward.

This was the stance of the bystander in the Holocaust – the vast majority of people (Yad Vashem puts it at around 80 per cent) who were like you and me. People like us were content to let their neighbours be carted off in the dead of night, or even in the middle of the day. They witnessed the line-ups, the beatings, the dogs. They smelled the smells of the chimneys and ovens. They knew what was going on, but they preferred not to know and then they did nothing.

Was this the right sort of behaviour?

But Jewish law is different. In contrast to what many have been told, Jewish law does not come primarily to legalize and hem in: the purpose of Jewish law is to disturb. It is not only about comforting the troubled, but also about troubling the comfortable. Jewish law – the way we go – does not wait until trouble troubles you.

Because waiting around doesn't help in the end. Often tragedy strikes in the most unexpected of ways. And the reaction then often is to blame everyone else. Those who want to get involved are told to 'butt out', 'mind your own business', or 'leave it to the experts'.

Unfortunately, however, the experts don't always get it right. And things are very different in the modern State of Israel, where people try to carry out Jewish law to the best of their ability on an everyday basis, and not simply as a tiny diaspora minority always looking over their shoulders and pretending that things are OK when they aren't.

So, on one occasion, early one morning, I was sat on a bus travelling down the busy Carmel road with cars flying in and out of the morning commute at break-neck speed, when our reverie was woken by a screeching of brakes. Opening our eyes more widely, we saw a number of women jumping out of a dozen or more cars on the busy main road, at risk to their own lives, and running over to the pavement where a woman dressed in a burka had fallen. And this is even though this woman was accompanied by a man we all assumed was her husband. Water was produced – an ambulance called and the woman escorted away to hospital. The Jewish women (you could tell by their garb) returned to their cars strewn all over the main street, and resumed driving as if nothing had happened. Nobody said anything and it was as if this were an everyday occurrence on top of the beautiful Carmel in Haifa.

This small incident taught me that no authentic life-choice is risk-free. And it is more than mere conscience. Conscience is what led the Nazis to murder their Jewish neighbours. Their ingrained sense of an ethical life-style based on strict and unwavering obedience to the categorical imperative of the German State and devotion to duty was such that they could follow orders to disembowel the 'enemy' who were their neighbours: women, children and babies, with impunity – all in the line of defending their leader and country.

The Jewish way, which Elijah is trying to teach to the children of Israel, the right way to go, is not easy at all. In the very last resort halacha may mean disobeying the law of the land, or at the very least falling out with family, friends and community, or even being totally shunned and despised.

But taking the safe way out is also never an option. And even though a certain amount of doubt is often necessary along the way, Elijah's challenge to the prophets of Baal is that man-made alternatives are no substitute for the real thing. We should never let the quest for a certainty that doesn't really exist paralyse our search for meaning and action by merely sitting on the fence and leaving it all to our elders and betters. Because that too is an illusion. After weighing things up, a decision is often necessary, and even if it isn't the perfect solution it is certainly better than doing nothing – and that is what the learning of Jewish law is all about and why Elijah, though hated and despised, was right to do what he did.

And this is why every Pesach we leave a glass of wine for the prophet Elijah to drink overnight, whereas the name of Jezebel has become a byword for evil and wickedness.

Dr Irene Lancaster is a Jewish academic, author and translator who has established university courses on Jewish history, Jewish studies and the Hebrew Bible.