Most existentialists are atheists like Jean-Paul Sartre. Yet, the Father of Existentialism, Soren Kierkegaard, believed in God, so being an existentialist does not exclude God, per se. It is interesting to read the atheist existentialists and notice that they find that life is absurd and amounts to nothing. Kierkegaard might agree and add, “Life is absurd without God.”
Atheist existentialists state that God is a conscience knowing being and man is not. That rather sounds like an admission that there is a God, but then they go on to say that the conscience of man does not exist. They also state that God’s existence and essence are one and the same. Sartre argues that man exists without any essence. In other words, existence precedes essence. We go through life making choices that determine our essence.
This actually makes sense, but it stops short of putting all the pieces together. The missing piece is perhaps the most important part of the message, which is God. Christians look forward to facing God when our existence and essence merge as one.
When existentialists refer to our existence as being a failure to fulfill, this is true without God. If we define God to be the creator, the missing invisible link to our creation, then that is the piece that is missing. God fulfills us. Nothing is missing when we have God.
Atheist existentialists declare that a non-belief is based on what is lacking. Thus, not believing in God is based on lacking a belief in God. There first must be a consciousness of God before there is a consciousness that there is no God. The first awareness of God is a positive consciousness. The follow-up belief that there is no God is a negative consciousness. Which is better the positive or the negative? And which came first? Why should the non-belief carry more weight than the belief?
When you analyze the evidence, there is none. You cannot prove or disprove God based on anything in our universe. Creation does not even occur in our universe. The First Law of Thermodynamics states that matter and energy are neither created nor destroyed in our closed system. You cannot state that there is a God based on experiences or observations (a posteriori). So, you must discover God by deduction (a priori).
How do we discover God through deduction? We think, therefore we exist. Existence is moving. The universe is moving. It is not logical that matter and energy would be moving without a stimulus or some type of start. This start is creation. A creation needs a creator. We deduce that there is a God. We know there is a God a priori.