What causes Brown to exclaim, "My faith is gone!"?

In the
forest one night, Goodman Brown witnesses a Black Mass, full of individuals worshipping the
Devil. He is surprised to see pious townspeople in attendance, including Goody Cloyse, his
catechism teacher when he was a child.

He holds on to his own faith and
stands strong against the Devil, however, until he realizes his wife Faith is one of the
attenders at this Satanic Mass. She appears to be asking the Devil to grant her some dark favor,
with encouragement from the others. When Goodman Brown sees her pink hair ribbon floating down
from a tree branch, he cries out: "My Faith is gone!" This...