His mother was a prostitute
John's father was a wealthy man who was married with a family
John's mother was a whore who died from a disease she caught
John never has the chance for a wife and family and envies that in David
It is a reminder what his father had and took for granted
His father was greed, greedy for money for sex
It is easier for a camel to pass though the eye of a needle that for a rich man to enter the kingdom of heaven,
Jesus tells us John's father is suffering in hell
Like David has, and like John's father had and took for granted
John was maybe always Envy and came to realise that fully through his Envy of David, a life he could never have
He takes David's life away and allows him to do the same to him with his Wrath
John probably believed he was going to Hell, having visited each sin upon the sinner and their murders as well as his suicide, as it was
He believes he is going down to whatever Circle of Hell he belongs in, those of you who have read Dante may have your interpretation of what John took from that, what he expected
Like the killer Jeremy in Hideaway, film based on the Dean Koontz book, who commits a murder suicide, asks Satan to take his soul, the goes on the journey ending up in the Lake Of Fire
John no doubt believes in the Hell he is going to
David now faces Hell on Earth, the optimistic future with his wife, and the child he just found out about, taken away by John, and the murder he committed means he faces a long jail term, possibly Life, and that as an ex cop
Though Apathy is not a Deadly Sin in the list of Seven, it is presented here as such
Apathy is what allows the other sins to happen
For evil men to do evil they just need good men to do nothing
The club owner has allowed the Lust crime to happen due to his Apathy
Somerset is aware of his own rising Apathy and plans to retire and move away
At the end he overcomes his Apathy, the only character to survive and find redemption
In Fight Club, Fincher's next film with Brad Pitt, the Father conversation between Tyler and Jack echoes this