Existentialism is a doctrine that states that every action means both an environment and a human subjectivity. There are two types of existentialists. The first ones are the Christians, such as Jaspers and Gabriel Marcel. The second ones are the existential atheists, namely the French existentialists.
Christians consider each person as the realization of a concrete conception that lives. On the other hand, atheistic existentialists state that is God does not exist, then there is someone whose existence comes before its essence. It means that a person first of all lives, examines himself and the world and determines himself.
The first principle of existentialism states that a man is what he has made of himself, nothing more. So each man is in possession of himself, as well as responsible for others. According to the existentialists a man is distressed, as he is choosing not only his own destiny, but makes a decision for the whole of mankind.
According to Dostoevsky, everything is allowed if there is no God. That is why the man is alone and he is always trying to find something to be dependent on within or outside himself. The man exists as soon as he realizes himself and always consists of his own actions. You are what you live.
Existentialism is a try out to underline the conclusions from the atheistic point of view. It does not necessarily mean plunging men into despair. Moreover, despair in existentialism meaning is not a type of disbelief. The existentialists think that the issue is not in God`s existence. All that man needs is to find himself and realize that he cannot rescue from himself. This way the existentialism is considered optimistic.
Existentialism is a doctrine that emphasizes the individual existence and determines the meaning of life.
Reference List:
1. Sartre, J.-P. (1946). Existentialism is a Humanism. Existentialism from Dostoyesvky to Sartre. Retrieved from https://www.marxists.org/reference/archive/sartre/works/exist/sartre.htm