Now, before we really dig into this symbol, check out these two passages:
In addition to that, escorted by only these men, he [Franz d'Epinay] was about to land on an island which certainly had a very religious name, but which appeared to offer Franz no greater hospitality than Calvary did to Christ, in view of the smugglers and the bandits. (31.100)
A little corvette was bobbing in a fairly large cove; it had a narrow hull and tall mast with a flag flying from the lateen yard and bearing Monte Cristo's coat of arms: a mountain on a field of azure with a cross gules at the chief, which could have been an allusion to his name (evoking Calvary, which Our Saviour's passion has made a mountain more precious than gold, and the infamous cross which his divine blood made holy) as much as to any personal memory of suffering in the mysterious night of the man's past. (85.124)
Here, Dumas is making a less than subtle analogy between the island of Monte Cristo and Calvary, the hill on which Jesus was crucified. Franz d'Epinay immediately makes the association between Monte Cristo – "Mountain of Christ" – and the place of Christ's execution. Dumas is a little more coy about his comparisons when he describes the Count's coat of arms, "a mountain with a field of azure with a cross gules" at the chief. In this context, "gules" simply means red; the Count's flag has what looks like a mountain with a red cross on top, against a blue background. Dumas goes on to tell us that this "could be" an allusion to the Count's name, a name which "could be," we can infer, an allusion to Calvary and the cross of Christ; or, that it could be some reference to his own personal suffering.
Of course, Dumas wants us to know that it is all those things: Monte Cristo's name – taken from the name of the island – and coat of arms recalls the suffering of Christ on the cross; Edmond Dantès's personal suffering reminds us of the same, and his rebirth as the Count reminds of Christ's resurrection. He, like Jesus, emerges from a cave – although in Edmond's case the cave contains a big chest of gold and jewels.
Now, if Dumas hasn't gotten through to you at this point, he really hammers things home in the last line of the last chapter of the book. "Who knows if we shall ever see them again," says Morrel, tears in his eyes. "My dearest," Valentine responds, "has the count not just told us that all human wisdom was contained these two words—'wait' and 'hope?'" (117.159). Dumas lets us know that the Count will be back again, like the Christian belief in the "second coming" of Christ.