Naturally the condition of bad faith is not always the case. Camus, for example, argues that the basic scene of human existence is its confrontation with this mute irrationality.
Marxism is unsurpassable, therefore, because it is the most lucid theory of our alienated situation of concrete unfreedom, oriented toward the practical-political overcoming of that unfreedom.
The notion that consciousness is not a thing is vital to Sartre.
Christianity is destroyed when it is pushed to tell the truth about itself, when the illusions of the old ideals are revealed. From the beginning existentialism saw itself in this activist way and this provided the basis for the most serious disagreements among French existentialists such as Sartre, Merleau-Ponty, and Camus, many of which were fought out in the pages of the journal founded by Sartre and Merleau-Ponty, Les Temps Modernes.
Unlike the traditional understanding of the human as a hypokeimenon Aristotle — what through the filtering of Greek thought by the Romans becomes substantia, that which supports all entities and qualities as their base and their ground — Dasein refers to the way which human beings are.
Who gave us the sponge to wipe away the entire horizon? I must either reject their claims or avow them. As with Kierkegaard's Knight of Faith, one cannot tell who is authentic by looking at the content of their lives.