This is an example of nihilism: a belief that life is pointless ("signifying nothing")
For a largely Christian Jacobean audience, this rejection of God's plan and the suggestion of a rejection of Heaven and Hell, would have been shocking
However, it is also a moment of pathos: the audience, despite his blasphemous words, would still feel sympathy for a once noble general who has lost his wife
It perhaps also represents a moment of anagnorisis: a tragic hero's realisation that all his actions were for "nothing" and that he will be defeated
"Life [...] is a tale told by an idiot, full of sound and fury, signifying nothing" Macbeth, Act V, Scene V analysis