How we cite our quotes: (Part.Book.Chapter.Line)
Quote #7
"Our marriage was impossible. I went to my grandfather, and he refused his consent. I have no fortune; neither have you." (4.14.7.10)
Marius doesn't know what he's going to do once his grandfather holds back his consent for the marriage with Cosette. It was a really, really big deal to marry against the wishes of your family, and walking away from Monsieur Gillenormand means that Marius will have no shot of inheriting the family fortune—meaning that he'd be dooming them to a lifetime of poverty and, yep, suffering.
Quote #8
Both were radiant in that supreme and unrepeatable moment, the union of youth and happiness. (5.6.2.6)
They're going to the chapel and they're finally going to get married. No cold feet, plenty of money, and (grand)parental approval: it looks like our young lovers are in for a long, happy life.
Quote #9
"A family! But I belong to no family, least of all yours. I am sundered from all mankind. There are moments when I wonder whether I ever had a father and mother. Everything ended for me with that child's marriage. (5.7.1.44)
Marriage makes a new family, but it destroys an old one. Valjean's situation is only an extreme example of this. Now that Cosette has a new family and Valjean must stay away from her to keep his checkered past from ruining her new life.