I think I've found it:
"The God of the Old testament is arguably the most unpleasant character in all fiction: jealous and proud of it; a petty, unjust, control freak; a vindictive, bloodthirsty ethnic cleanser; a misogynistic, homophobic, racist, infanticidal, genocidal, filicidal, pestilential, megalomaniacal, sadomasochistic, capriciously malevolant bully."
It's at the start of Chapter 2.