Atheism and irony in Conrad's Victory

Heyst and the young English woman whom he'd rescued from near captivity and brought to live w/ him on his near-deserted island, Alma, whom for some reason he renames Lena, you tell me, have been living there for 3 months with, seemingly only one other person, the mysterious Chinese servant, Wang. H and L go for a walk to the highest point on the island - Wang seems continuously to spy on them and then to disappear somehow - and Lena feels uneasy looking at the broad expanse of ocean: they're so alone, she realizes. They sit down and Heyst in his awkward manner tries to flatter her, then goes on to speak of his philosophy of life (adapted from his famous and austere philosopher father): man is insignificant, there is no god, there is no purpose to life - all of which explains his life as a solitary wanderer. She is afraid of him. She has heard that he killed a man - the man was Morrison, who died on a return visit to England; Heyst protests that he actually saved M and devoted his life to him, against his will, which is true. Then he says how he has never loved a woman: How to interpret that is a good question. Does he mean he has never been in love? Or in fact that his a virgin (35 years old)? Conrad dances around that question - but H advances on Lena and they do have sex - between the chapters, by the way. After they have sex and return to the small house, H reads more philosophy while Wang almost magically prepares dinner for the two; they are perhaps, just maybe, on the verge of happiness - but we know (and short peak ahead tells me this is coming up soon) that Schomberg's emissaries, Ricardo and plain Mr. Jones, are on their way to the island to rob H of the treasure that he doesn't possess. What's with all the philosophy? It seems that Conrad, in the great modernist tradition, is an being an ironist here - we knowing much more about the characters than they know or realize about one another: As H talks about the world being godless and man being w/out purpose, we also see, inevitably, that he is godlike - rescuing a woman on the verge of captivity and ruin - and that in fact the two of them are like modern-day, tropical Adam and Eve, alone (nearly) in their garden, living in innocence, sheltered for the moment from the dangers of the world (and the pleasures and obligations of the world)  - and the question is, now that they have had sex, are they fallen? or awakened?