In Jean-Paul Sartre's Existentialism, he speaks of two different types of existence. These are "essence before existence" and "existence before essence." "Essence before existence" is when something is created because it already serves a purpose. For example, when Eli Whitney created the cotton gin, it already served a purpose therefore it was created. Sartre argues that humans, on the other hand, is an example of "existence before essence." He says that humans did not serve a purpose before they were created.  
In Steven Hawking's Is Everything Determined, Hawking questions whether or not everything is already pre-determined. After arguing both sides of pre-determination, whether or not it exists or not, Hawking decides that everything is already determined but he expands on how and why everything is pre-determined. He says that although everything is pre-determined, humans are not aware of that of which is already determined. Things can alter the already pre-determined such as free-will.

I agree with Stephen Hawking, partially because I grew up in a Christian private school my entire life. I believe that everything is already pre-determined, because there is a God, although the already pre-determined path can be altered due to the fact that God gave humans free-will. I do not agree with Sartre, because I believe that humans did a serve a purpose before creation, therefore they do not follow underneath the category of "existence before essence."