The Iceman Cometh by Eugene O'Neill:
It’s funny Mother kept in touch with you so long. When she’s finished with anyone, she’s finished. She’s always been proud of that. And you know how she feels about the Movement. Like a revivalist preacher about religion. Anyone who loses faith in it is more than dead to her; he’s a Judas who ought to be boiled in oil. Yet she seemed to forgive you.
She didn’t, don’t worry. She wrote to denounce me and try to bring the sinner to repentance and a belief in the One True Faith again.