The rejection of established religion is shown by whom in "The Open Boat"?

The Correspondent is the character who rejects all gods, all religions, all order and stability in the natural world. He is the ultimate existentialist, regarding his situation and that of the other men as thoroughly absurd as they flounder all alone in a world (symbolized by the cruel sea) utterly indifferent to their fate.
But like a number of existentialists, the Correspondent attempts to supply the deficiencies of religious faith with a rival belief system, one more in keeping with the explicitly naturalistic tone of "The Open Boat." The Correspondent rejects God and instead embraces a human brotherhood that provides a sense of solidarity in the midst of an increasingly desperate struggle against the forces of nature. But as the story progresses, the Correspondent comes to realize that he has simply replaced one religious faith with another. He has unconsciously been avoiding a confrontation with the true hopelessness of his situation and that of the other men.
There is now nothing for it but to take their chances and make a swim for it. The "subtle brotherhood of men" has disintegrated, and now it's every man for himself. Once again, they are all alone in the world, an existentialist metaphor if ever there was one. We are not in the least bit surprised, then, when Billie the oiler, the most hopeful and optimistic character in the story, ends up dead. He has been swimming against the tide, both literally and figuratively.