Sartre's Philosophy Of Atheistic Existentialism

In our present society, we all are able to live and interact with each other in a community, that is, a group of people who live in close association with one another and share common attitudes, identity, or interests, under an established and enforced code of law. This system of justice primarily projects a standard of basic ethics which are generally agreed upon despite of different belief systems, cultural norms, and religion. For example, theft is clearly not tolerated by our justice system and may be considered an act founded upon bad morals. Now imagine a society without any standard definition of morality whatsoever because everyone has crafted their respective ideas of justice and morals which may or may not agree with one another.
Rather than deny or attempt to disprove God’s existence, it only asserts that if God does not exist, then Man is the only one whose “existence precedes essence.” Even if God is present, his existence would not change this idea or make any difference. As one whose “existence precedes essence”, Man is initially nothing when he first comes into the world because he does not have any pre-essential properties or purpose. He merely exists until he becomes what he conceives and wills himself to be later
In addition, who is to say that one individual’s ideas of moral concepts supersedes the ideas of others’? Sartre does argue that “we may judge that certain choices are based on error and others on truth. We may also judge a man when we assert that he is acting in bad faith…my answer is that I do no pass moral judgment against him, but I call his bad faith an error” (Sartre 47). Sartre agrees that we cannot pass moral judgments, but at the same time, how can we form judgments out of good or bad faith as well as error and truth? Robert Alexy, who argues that absolute, objective, or necessary moral elements exist in Law, Morality, and the Existence of Human Rights, affirms, “If there exist no necessary moral elements, for instance human rights or universal principles of justice…extreme injustice would not exist either” (Alexy 6). Good faith is the only criterion which Existentialism acknowledges, yet it is an extremely vague term that I cannot envision its realistic applications in an Existentialist world. It does not seem logical that Existentialism recognizes good faith because there is no overarching concept of what is considered good or bad. Therefore, in Existentialism, we do not have the authority to consider someone to be in good or bad faith. If we were to apply this to a