Q: Do our decisions affect the Creator?
A: No.
Q: Does only the Creator decide what we must do?
A: Yes. Ordinary people do not influence the Creator, because they have no means to do so. They have no screen. But he who becomes a “man” in the Kabbalistic sense of the word - a person with a screen-can influence the Creator and the entire creation. He becomes the leader of creation in place of the Creator; an equal partner to the Creator.
As long as you have not become a “man” - a person with a spiritual degree - and are still captivated by your corporeal nature, you are incapable of making any decisions because all you can see is this world.
What do you see before you that would enable you to decide what to do? In this world, you are given the illusion of freedom, and are taught to behave like a blind kitten. When that truth is revealed to you, you’ll see how wrong you were.
The Creator is almighty precisely because He gives man everything: freedom of choice and the strength to act, understanding and attainment of the laws of reality. Upon choosing spirituality, man wishes to cleave to the Creator. This desire stands far above his self-benefit; it pertains to the attribute of being “for the Creator.”
In other words, man sees the Creator as the ultimate good and wishes to serve Him.