What existentialist philosopher is not an atheist?

Three existential philosophers that were not "Atheist", meaning that they have a lack of belief in a God, or a group of Gods. Getting in to Atheism is a whole different subject that we shall not delve to deeply in just for the sheer fact that different people have their own personal ideas on what it really is -- But, the three philosophers that I found that were NOT Atheist, had a Christianity background. The names of these gentleman are Paul Tillich, Gabriel Marcel, and John Macquarrie. Given that these gentleman professed Christian faith, doesn't mean that any other known Existential Philosophers were not Atheist. There are other religions and beliefs that many held dear, but once again.