Smartphones can do amazing things – few more amazing than Waze, the Israeli-designed satellite navigation system acquired by Google in 2013. But there is one thing even Waze cannot do. It can tell you how to get there, but it cannot tell you where to go. That is something you must decide.

The most important decision we can make in life is to choose where we want eventually to be. Without a sense of destiny and destination, our lives will be directionless. If we don’t know where we want to go, we will never get there no matter how fast we travel. Yet despite this, there are people who spend months planning a holiday, but not even a day planning a life. They simply let it happen.

That is what our parsha is about, applied to a nation, not an individual. God, through Moses, set out the stark choice. “If you follow my statutes and carefully obey my commands, I will send you rain in its season and the ground will yield its crops and the trees their fruit … I will grant peace in the land, and you will lie down and no one will make you afraid.”

If, on the other hand, “You do not listen to me, and do not keep all these commands…” then disaster will follow. The curses set out here at length are among the most frightening of all biblical texts – a portrait of national catastrophe, bleak and devastating.

The entire passage, both the blessings and the curses, can be read supernaturally or naturally. Read the first way, Israel’s fate, at least in biblical times, was a direct result of its faithfulness or lack of it to the Torah. God was constantly intervening miraculously in history to reward the good and punish the bad. Every drought and famine, every bad harvest or military defeat, was the result of sin. Every peaceful and productive year was the result of obedience to God. That is how Israel’s prophets understood history.

But there is also a more naturalistic reading, which says that Divine providence works through us, internally rather than externally. If you are the Israelites in the land of Israel, you will always be surrounded by empires and enemies bigger and stronger than you are. You will always be vulnerable to the hazards of rainfall and drought because Israel, unlike the Nile Delta or the Tigris-Euphrates valley, has no natural, reliable, predictable supply of water. You will always, therefore, find yourself looking up to the heavens. Even quite secular Jews often understand this – most famously David Ben Gurion when he said, “In Israel, in order to be a realist you have to believe in miracles.”

On this reading, the way of life set out in the Torah is unique in ways that are natural rather than supernatural. It is indeed the word of God, but not God as a perpetual strategic intervener in history, but rather, God as guide as to how to live in such a way as to be blessed. The Torah is a set of instructions for life issued by the Designer of life. That is what the sages meant when they said that at the beginning of time, “God looked into the Torah and created the world.” Living according to the Torah means, on this view, aligning yourself with the forces that make for human flourishing, especially if you are a tiny people surrounded by enemies.

What was unique about the society envisaged by the Torah is that in it every individual mattered. Justice was to be paramount. The rich could not buy special treatment and the poor were not left destitute. When it came to communal celebrations, everyone – especially the orphan, the widow, the stranger – was to be included.

Everyone had at least some share in the harvest of grain and fruit. Employers were to treat employees with fairness and sensitivity. Even though there were still slaves, one day in seven they would enjoy the same freedom as their owners. This meant that everyone had a stake in society. Therefore they would defend it with their lives. The Israelites were not an army conscripted by a ruler for the purpose of his own self-aggrandisement. That is why they were capable of defeating armies and nations many times their size.

Above all, they were to have a sense of destiny and destination. That is the meaning of the keyword that runs like a refrain through the curses: keri, a word that appears seven times in our parsha and nowhere else in Tanakh. “If you walk with Me with keri … then I will walk with you with keri.”

There are many interpretations of this word. Targum Onkelos reads it as “hard-heartedly”, Saadia as “rebelliously”, Rashi as “treating as a casual concern.” Others understood it as “harshly”, or “with hostility”. Maimonides, however (partially echoed by Rashi, Rashbam, Ibn Ezra, Chizkuni and others), understands it as related to the word mikreh, meaning “chance”. Hence the meaning of the passage according to Maimonides is: “If you believe that what happens to you is simply a matter of chance, then, says God, I will leave you to chance.”

On this reading, the book of Vayikra ends as it began, with the fateful choice between mikra (with an aleph) and mikreh (with a heh): between seeing life as a call, a summons, a vocation, a destiny, and seeing it an accident, a random happening with no ultimate meaning whatsoever.

So it is in the life of nations and individuals. If you see what happens to you as mere chance, your fate will be governed by mere chance. That is what the sages meant when they said, “Wherever [the Torah] says, ‘And it came to pass’, it is always a prelude to tragedy.” If you simply let things come to pass, you will find yourself exposed to the vagaries of fortune and the whims of others. But if you believe you are here for a purpose, your life will take on the directedness of that purpose. Your energies will be focused. A sense of mission will give you strength. You will do remarkable things.

That was the special insight Jews brought to the world. They did not believe – as people did in ancient times and as atheists do today – that the universe is governed by mere chance. Was it mere chance that a random fluctuation in the quantum field produced the Big Bang that brought the universe into being? Or that the universe just happened to be regulated by precisely the six mathematical constants necessary for it to give rise to stars and planets and the chemical elements essential for the emergence of life? Was it mere chance that life did in fact emerge from inanimate matter? Or that among the hundred million life forms that have existed on earth, just one, Homo sapiens, was capable of asking the question “Why?”

There is nothing self-contradictory about such a view. It is compatible with all the science we now know, perhaps with all the science we will ever know. That is the universe as keri. Many people think this way. They always did. On this view, there is no “Why,” not for nations, and not for individuals. Life just happens. We are here by accident.

Jews believed otherwise. No one said it better than the Catholic historian Paul Johnson:

No people has ever insisted more firmly than the Jews that history has a purpose and humanity a destiny. At a very early stage in their collective existence they believed they had detected a divine scheme for the human race, of which their own society was to be a pilot. They worked out their role in immense detail. They clung to it with heroic persistence in the face of savage suffering. Many of them believe it still. Others transmuted it into Promethean endeavours to raise our condition by purely human means. The Jewish vision became the prototype for many similar grand designs for humanity, both divine and man-made. The Jews therefore stand right at the centre of the perennial attempt to give human life the dignity of a purpose.

The people who change the world are those who believe that life has a purpose, a direction, a destiny. They know where they want to go and what they want to achieve. In the case of Judaism that purpose is clear: to show what it is to create a small clearing in the desert of humanity where freedom and order coexist, where justice prevails, the weak are cared for and those in need are given help, where we have the humility to attribute our successes to God and our failures to ourselves, where we cherish life as the gift of God and do all we can to make it holy. In other words: precisely the opposite of the violence and brutality that is today being perpetrated by some religious extremists in the name of God.

To achieve this, though, we have to have a sense of collective purpose. That is the choice that Moses, speaking in the name of God, set before the Israelites. Mikra or mikreh? Does life just happen? Or is it a call from God to create moments of moral and spiritual beauty that redeem our humanity from the ruthless pursuit of power? “To give human life the dignity of a purpose.” That is what Jews are called on to show the world.

For more from Rabbi Sacks, please visit www.rabbisacks.org