At what precise moment does Goodman Brown lose his faith?

Although Goodman Brown
cries that his Faith is gone when he sees her pink ribbons, he later asks, "'But, where is
Faith?'" Further, "hope came into his heart" at the witches' Sabbath.  Brown and
Faith are brought forth as "converts," and when they are brought together at the front
of the unholy congregation, Goodman Brown looks at his wife and cries, "'Faith! [....] Look
up to Heaven, and resist the Wicked One!"  

To my mind, his hope of
seeing Faith and then his instruction to her to resist the Devil indicates that he hasn't yet
lost his faith yet, at least not fully.  At this point,...