how is allusion used

"One allusion in the novel is found in "The Sieve and the Sand" when Faber reads from the book of Job. This book of the Old Testament is the story of Job - who is the victim of a dispute between God and Satan, to see if this human, when put through as much difficulty as Satan can manage - will remain faithful to God. Faber encourages Montag to continue doing what he thinks is right, despite the difficulty. In the end, Job does remain faithful - and is greatly rewarded as a result. The unspoken connection here is that Faber believes Montag will feel rewarded in the end."