The Torah’s position is clear: Although it was common for the nations of ancient Canaan to seek counsel from astrologers, for a Jew, astrology is off limits.

For these nations that you are possessing - they hearken to astrologers and diviners; but as for you - not so has Hashem your G‑d given for you.1

The Jews may wonder, how will we survive with this disadvantage? While the other nations could look to their astrologers to guide them in everything from planning war to picking stocks, we will be in the dark! But Moses puts them at ease, reassuring them that they will have a different source of information:

A prophet from your midst, from your brethren, like me, shall Hashem, your G‑d establish for you—to him shall you hearken.2

The question, of course, is what is the difference between a prophet and an astrologer? If listening to an astrologer is so terrible, why are we not only permitted, but in fact commanded, to listen to the prophet? The question intensifies when one realizes that while astrologers are not always accurate predictors of the future, prophets have a far from perfect track record too. Perhaps the most famous prediction gone wrong was the prophecy of Jonah, which warned that the great city of Nineveh would be destroyed 40 days henceforth, when in fact no such thing happened. The people of Nineveh repented and G‑d averted the terrible decree.

Why wasn’t the prophecy realized? Only a good prediction must materialize; G‑d is compassionate and may avert a negative event up until the very last moment.

The astrologers, by contrast, claim to be straightforward and leave no room for their predictions to change.

Why then would we want to listen to a prophet, whose prophecy may or may not come to fruition?

Although it may not seem so on the surface, the prophet and the astrologer are not actually in the same line of business. Their mission statements could not be further apart.

The astrologer predicts a person’s destiny based on his or her personality, nature, or spiritual make-up. In some ways, the information is very useful. Why should a person spend a lifetime trying to discover which things he will succeed or fail at, when he can presumably take a shortcut and get the information directly from an astrologer? But implied in the message of the astrologer is that a person cannot change; his nature is his nature, and that determines his future.

The prophet, however, is not in the business of predicting the future. The prophet’s role is to inspire a person to break out of his or her nature, to break free of his destiny, and to understand that there is no barrier to spiritual growth that cannot be shattered. The astrologer limits a person, while the prophet liberates him.

When Nineveh was spared, Jonah was terribly angry. Initially, he had tried to escape his mission precisely because he was afraid that G‑d would not ultimately destroy the city, putting his reputation as a professional predictor of the future into severe jeopardy. No one would ever trust his predictions again. G‑d was upset at Jonah’s anger, precisely because Jonah had entirely missed the point of prophecy. He did not realize that had his prediction succeeded, his mission would have failed, for the prophet’s mission is not to define a person’s destiny, but to tell him that he can change and become a new person anytime he so desires.

Although we are no longer in the era of the prophets, we must take the message to heart, ignore our inner astrologer and listen to our inner prophet. The greatest impediment to growth, both spiritual and material, is the voice inside us which tells us that after all these years we know who we are, we know our strengths and weaknesses, we know where we will succeed and where we will fail, what we can hope for, and what we shouldn’t even dream about. We have it all figured out.

The commandment to heed the prophet, in the portion of Shoftim, is read during the month of Elul, the month of introspection and repentance leading up to the New Year. And we read the book of Jonah on Yom Kippur, the Day of Atonement, because as we prepare for the New Year, we must listen to the voice of prophecy. We must understand that whatever our nature is, we cannot and must not allow it to limit us. We must understand that G‑d gives us the power to break out of our limitations, to change, and to become the person we know we should be.