I heard a good explanation to this from Rabbi Pincus  that I would like to expound on.  He used a story form the Gemara Ta’anis 25 a: 

Rabbi Elazar ben Pedat was hard-pressed for money. Once an act of bloodletting was performed on him,  and Rav Elazar was very poor so poor that he was sick had nothing to eat but garlic and in his state of health fainted [fell asleep] from the strength of the garlic.  He meets Hashem in his slumber.  He requested of Hashem that he not be poor anymore. Hashem said that because of mazal (astrology) that he could not change his fortune without starting the world from a new and then only maybe things would be different.  After asking if he had lived out most of his life, the thought of having to suffer all that again he decided to say that he does not want to change things. As a reward, Hashem granted him a big present in the next world. With which he was not satisfied and asked for more since this world is only temporary and the next will be for eternity.  Hashem reply what will be left for your friends if i give it all to you. Rav Elazar responded stating that he is not a man who is limited but rather unlimited.  Hashem was please with his answer but also unpleased.  Hashem gave him a ‘patch’ as if to say “now you got it why did you not understand that before when I told you i could not make you rich” 

 

Hashem was please with his answer but also unpleased.  Hashem gave him a ‘patch’ as if to say “now you got it why did you not understand that before when I told you i could not make you rich” Hashem is not limited now in this world nor in the next.

 

Is there a set destiny or are things up for change?

It is written about Mazel ‘astrology’ in the Prophets the star systems are called ofanim ‘wheels’.

  The Zohar concludes that all that Yehezkel revealed was necessary for the people of Israel to know in order to survive the ensuing exile. They were accustomed to great delights while living in the land of Israel, and the Babylonian exile was going to be harsh. Therefore they needed to receive the knowledge of Ma’aseh Merkava dressed in this form, as the Gemara says (Hagiga, 13b),

The book ” שער האמונה ויסוד החסידות ” continues

it is written in Yehezkel, 1:1, “and the form of their faces was the face of the man, and the face of the lion to the right, etc.” That is to say, the face of man was included in all four faces on the chariot...