How does Reverend John Hale change throughout The Crucible by Arthur Miller?

The Reverend Hale enters in act 1 with the assurance of an expert
who has been invited because of his specialist knowledge. His books, he says, are heavy because
they are "weighted with authority," and he is given to making weighty pronouncements,
including one so absurd that Miller in the stage directions expresses surprise that audiences do
not laugh at it:

Now let me instruct you. We cannot look
to superstition in this. The Devil is precise

When Hale
visits the Proctors in act 2, he admits that he comes "without the court's authority,"
but he seems to regard his own authority as a minister and an expert on witchcraft as sufficient
for him to question John and Elizabeth and ascertain whether they are good Christians or not. By
the end of the act, however, his certainty is badly shaken when Elizabeth is arrested. Proctor
calls him a coward and a "broken minister" and compares him to Pontius Pilate, and
Hale is unable to respond, thrown into confusion by the unjust and...