The Jewish community is currently in the penitential month of Elul, when we recite Selichot, asking G-d for forgiveness.

Observant Judaism believes in stages. A sudden conversion or change of heart is regarded with suspicion and this is for good reason. In Jewish history we have experienced fellow Jews going off the rails due to epiphanies that have led to destruction. In some cases new sects have been formed, and in others novel interpretations have been formulated that contradict the teachings of observant Judaism.

So any sort of repentance, or conversion, whether of oneself or of people who want to join the observant Jewish community, takes a very long time. The journey includes Torah learning of necessity, leading to cultivation of character traits, which in turn lead to actions geared towards G-d, known in Hebrew as the 'mitzvot', but always with kavvanah (right intention).

As we gear up for the High Holy Days of Jewish New Year (Rosh Hashanah) and the Day of Atonement (Yom Kippur), we gradually wean ourselves into the proper state of mind open to the incredible sounds of the shofar which wake us up from our slumber. The Elul Selichot service is part of this process and here is a flavour from a local synagogue.

Many Christians see things through their own prisms and regard rabbis as Jewish priests or vicars. This is the opposite of the case. The synagogue rabbi is an employee of the synagogue and it is up to congregants to choose him and if necessary replace him with someone else. The rabbi emphatically does not repent on behalf of everyone else and in many synagogues a rabbi is deemed unnecessary – the service being taken by knowledgeable members of the congregation.

In Judaism every person is equal in the sight of G-d. We are all part of G-d's creation. And every person is equally responsible for their actions. The rabbi does not grant us absolution. There is no Jewish intermediary to G-d.

The role of the rabbi (if such a person exists in the synagogue) is to encourage education in Torah for both men and women, the very young and the very old. This learning is not academic. It is essential to learn, in order to understand G-d's word, to argue over this word with a learning partner, to hone one's character traits as a result, and then to go out into the world and act on this theory and practice.

This is what is meant by being 'a light unto the nations'. Action is paramount in Judaism. This is the moment that this realisation came home to one young Jewish man living under the Jewish Mandate period in Israel. This young man, aged 20, realises that learning Torah and commentaries are simply not enough. The Jewish people now has to act. And being humble – like Moses – entails utilizing leadership qualities for the greater good of one's people. He wrote: 'I dreamed a dream. And in that dream I envisioned a group of Torah scholars and Yeshiva students living the words of verse 7 of the wonder Psalm 149: "Let the high praises of G-d be in their mouths and a two-edged sword in the hands."'

Thus started the idea of the hesder Yeshiva movement, where learning and training to fight for one's country go hand in hand. At that time back in 1947 there was an initial reluctance by the average Yeshiva student to join such a scheme.

'This was not enough for me. The dream was not being fulfilled. I thought that if I myself made the first move, then others would follow me. I no longer allowed false modesty to hold me back – two sides of the same coin – theory buttressed by practice....

'I didn't believe it was feasible to serenely study Torah amid firestorms of shells detonating all around us, with our comrades dying by the dozen.... I did not believe in a heavenly Jerusalem if there was no earthly Jerusalem here below.'

Many people would be stunned at the idea of a rabbi deciding to fight for what he believes in. But I believe that this is because 2000 years of Jews in Diaspora has Christianized the Jewish religion to the extent that many rabbis are now simply vicars in all but name – and this is not good for the future of Diaspora Judaism.

Twelve years ago to the day, on August 16th 2006, I landed in Israel, ready for my new life in Haifa, which was enveloped in the 2nd Lebanon War. I had chosen Haifa as my home because it was in the north-west. It was on the sea. It had a great musical tradition and two superb universities. It was also beautiful, more relaxed than most Israeli cities, and with a very diverse community.

I will never forget on arrival in Haifa when the 20-year-old student, now nearly 80, invited me into his home and asked me, in the wake of the 2nd Lebanon War bent on destroying Haifa (and he refused to abandon the city when the vast majority of pensioners fled south to escape the bombardments), for my advice on whether or not to accept the invitation he had received from the then Archbishop of Canterbury to consider working with the Church of England to overcome centuries of hostility.

'What do you think?' he said. 'Have they truly repented?' I thought about this.

'They may not have repented and maybe never will. But at least they will have a chance to make some amends by working with you as the representative of the Chief Rabbinate of the State of Israel.'And so it happened.

Is everyone capable of repentance? In theory probably 'Yes'. But in practice probably 'No'. There are some crimes so heinous (and we in the UK are learning about some of these on a daily basis as I write) that no matter how many times a truly evil person says 'Sorry', it is obvious to all that he is simply making it up as it goes along.

Judaism does not believe in 'Original Sin'. We believe that we are born with two instincts, for good and for evil. We have free choice all the way. We are all capable of not just listening to the shofar but heeding what it means.

For this we need learning, humility, good deeds and the openness for real change. Unfortunately, in our tunnel-visioned world, openness to the sound of the shofar is not always evident, and laxity in learning, humility, good deeds and openness has led to very great difficulties in the capacity to change.

For as it states in Isaiah 6:10: 'This people's heart is becoming fat and their ears are becoming heavy. And their eyes are becoming sealed. Lest they see with their eyes and hear with their ears and understand with their heart and convert and be healed.'

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