The first three quotes relate to social class, while the last two quotes are about deception.
"I am still a little afraid of missing something if I forget that, as my father snobbishly suggested, and I snobbishly repeat, a sense of the fundamental decencies is parceled out unequally at birth."
"When I came back from the East last autumn I felt that I wanted the world to be in uniform and at a sort of moral attention forever; I wanted no more riotous excursions with privileged glimpses into the human heart. Only Gatsby, the man who gives his name to this book, was exempt from my reaction—Gatsby, who represented everything for which I have an unaffected scorn."
"I told that boy about the ice." Myrtle raised her eyebrows in despair at the shiftlessness of the lower orders. "These people! You have to keep after them all the time."
"You see," cried Catherine triumphantly. She lowered her voice again. "It's really his wife that's keeping them apart. She's a Catholic, and they don't believe in divorce." Daisy was not a Catholic, and I was a little shocked at the elaborateness of the lie."
"It made no difference to me. Dishonesty in a woman is a thing you never blame deeply – I was casually sorry, and then I forgot. It was on that same house party that we had a curious conversation about driving a car. It started because she passed so close to some workmen that our fender flicked a button on one man's coat."