How does Albert Camus show us his beliefs through Meursault in the Stranger

Meursault, the narrator and main protagonist in Albert Camus's existentialist novel The Stranger, shows many characteristics held to the philosophy of absurdism. As the novel begins, Meursault learns of the death of his mother and responds with indifference. This immediately shows Camus's philosophy of absurdism; life is absurd, and so, therefore, is death. Later, when he interacts with his mother's friends, Meursault notices,

that's when mother's friends came in...I saw them more clearly than I had ever seen anyone...but I couldn't hear them and it was hard for me to believe they really existed (15).

This uncertainty of the actual existence of his mother's friends is a prime example of the philosophy of the absurd, particularly solipsism (which operates under the belief that only one's own mind is guaranteed to only exist, while the existence of others may only be imagined). Camus's philosophy of absurdism follows a similar path, for Camus believed that the meaning of life—should it even exist—cannot be known or found by the human mind. Meursault's lack of confidence in the suggestion that his mother's friends may not actually exist is absurd; in his mind, they may not exist, but there's certainly no way to know either way.
After killing a man and being sentenced to death, Meursault rejects the prison Chaplain who tries to push religious absolution upon him. After rejecting his offer, Meursault eventually goes into a rage-filled rant, in which he summarizes his entire philosophy:

"What difference could they make to me, the deaths of others, or a mother's love, or his God; or the way a man decides to live, the fate he thinks he choosins, since one and the same fate was bound to "choose" not onl me but thousands of millions of priveledged people...and what difference could it make if, after being charged with murder, he were executed because he didn't weep at his mother's funeral, since it all came to the same thing in the end?" (152).

This, then, brings back to Meursault's rejection of mourning. He doesn't mourn for his mother because he believes all people die. Life cannot be mourned, in Meursault's mind, because it is entirely too absurd. And so, the absurdist philosophy of Albert Camus, is sketched in great detail by the character of Meursault.