How we cite our quotes:
'How could you help yourself from being married! [...] Was it my mother's project, then?'
'The Lord bless you, Arthur, and forgive me the wish!' cried Affery, speaking always in a low tone. 'If they hadn't been both of a mind in it, how could it ever have been? Jeremiah never courted me; t'ant likely that he would, after living in the house with me and ordering me about for as many years as he'd done. He said to me one day, he said, "Affery," he said, "now I am going to tell you something. What do you think of the name of Flintwinch?" "What do I think of it?" I says." Yes," he said, "because you're going to take it," he said. "Take it?" I says. "Jere-MI-ah?" Oh! he's a clever one! [...] Jeremiah then says to me, "As to banns, next Sunday being the third time of asking (for I've put 'em up a fortnight), is my reason for naming Monday. She'll speak to you about it herself, and now she'll find you prepared, Affery." That same day she spoke to me, and she said, "So, Affery, I understand that you and Jeremiah are going to be married. I am glad of it, and so are you, with reason. It is a very good thing for you, and very welcome under the circumstances to me. He is a sensible man, and a trustworthy man, and a persevering man, and a pious man. "What could I say when it had come to that? Why, if it had been--a smothering instead of a wedding,' Mrs. Flintwinch cast about in her mind with great pains for this form of expression, 'I couldn't have said a word upon it, against them two clever ones.' (1.3.90-98)
Affery is so terrified of Mrs. Clennam and Flintwinch that she cannot even imagine a way to avoid doing whatever they demand of her. Also, that's a fantastic bit about the wedding being just like a "smothering." Imagine being invited to something like that.
Woe to the suppliant, if such a one there were or ever had been, who had any concession to look for in the inexorable face at the cabinet. Woe to the defaulter whose appeal lay to the tribunal where those severe eyes presided. Great need had the rigid woman of her mystical religion, veiled in gloom and darkness, with lightnings of cursing, vengeance, and destruction, flashing through the sable clouds. Forgive us our debts as we forgive our debtors, was a prayer too poor in spirit for her. Smite Thou my debtors, Lord, wither them, crush them; do Thou as I would do, and Thou shalt have my worship: this was the impious tower of stone she built up to scale Heaven. (1.5.28)
For Mrs. Clennam, the appeal of Christianity is how powerful God is to do damage to whomever deserves it. She doesn't fully get the religion; her version of it is almost like worshipping a superhero or something.
Tip tired of everything. With intervals of Marshalsea lounging, and Mrs. Bangham succession, his small second mother, aided by her trusty friend, got him into a warehouse, into a market garden, into the hop trade, into the law again, into an auctioneers, into a brewery, into a stockbroker's, into the law again, into a coach office, into a wagon office, into the law again, into a general dealer's, into a distillery, into the law again, into a wool house, into a dry goods house, into the Billingsgate trade, into the foreign fruit trade, and into the docks. But whatever Tip went into, he came out of tired, announcing that he had cut it. Wherever he went, this foredoomed Tip appeared to take the prison walls with him, and to set them up in such trade or calling; and to prowl about within their narrow limits in the old slip-shod, purposeless, down-at-heel way; until the real immovable Marshalsea walls asserted their fascination over him, and brought him back. (1.7.75)
The novel is fascinated with the way some ideas can grip the mind and not let go. Tip has been so shaped by growing up with criminals, conmen, and other various lowlifes that he will never outgrow his childhood fascination with them.