Why are the gravediggers debating about whether Ophelia

deserves a Christian burial?

They are debating this as her cause of death was s uicide.

Explanation:

One argument is that the Church forbade burials when a deliberate death happened on consecrated ground, as Ophelia's did. The argument against this is that Ophelia's death was not in fact a s uicide but accident, or if it was s uicide it was simply a product of her madness and not a reflection on Ophelia's true Christian soul.