What is Existentialism? (Post 2)

I was thinking a lot when I was reading the "What is existentialism?" article. I'm currently involved in a bible study at church, so I'm feeling like I'm going to have my own little crisis during this class! When it talked about the Father of existentialism, Dane Soren Kierkegaard, about the irony of him having a belief in God, but he thought of himself as an existentialist because he couldn't prove that God actually existed, that really hit me hard. In essence, I can't prove definitively that God exists, but I can't prove that he doesn't either. I have a belief in God, but have questioned what my path is. I understand that God gives me choice in my life and that I'm responsible for the outcome, and isn't that what the article says Jean Paul Sartre said part of the definition of existentialism was?

I suppose in short, I left with more questions in my mind than answers. I feel I have a good grasp on the basic "definition" of the term, but I am questioning the holes that I'm finding in the theories. Or... maybe I'm thinking too much?!