From the context of this sentence, we know that the mosque is talking about a place because it talks about "built over the years" then it mentions "people across the border" and "refugees" which hints at the Muslim religion and "a place to say their prayers" tells us that it is a building/temple for that religion.
Answer: Whereas Stephen Crane's idea of survival through social togetherness is very similar to that of Jack London, Crane introduces ideas of hierarchy and morality