What has been revealed about the townspeople's belief in witchcraft?

Abigail tells her uncle, Reverend Parris, that "the rumor of witchcraft is all about" at the very beginning of Act One.  The people in town know of Betty Parris's illness, and there is a rumor that she flew.  Obviously, then, we learn fairly early that the townspeople have no problem whatsoever with believing in witchcraft.

Further, Parris panics when he thinks that Abigail and Betty have been "traffick[ing] with spirits in the forest" because any...

Abigail tells her uncle, Reverend Parris, that "the rumor of witchcraft is all about" at the very beginning of Act One.  The people in town know of Betty Parris's illness, and there is a rumor that she flew.  Obviously, then, we learn fairly early that the townspeople have no problem whatsoever with believing in witchcraft.

Further, Parris panics when he thinks that Abigail and Betty have been "traffick[ing] with spirits in the forest" because any hint of witchcraft in his home would spell ruin for his reputation and position in town.  He also worries that "[Abigail's] cousin's life" may be in jeopardy as a result of their illicit behaviors.  Thus, he clearly believes in witchcraft, the conjuring of spirits of the dead and being harmed by them.  

Moreover, when Mrs. Putnam arrives, she says that Parris's slave, Tituba, knows how to conjure the dead, and she admits that she sent her daughter, Ruth, to Tituba to call up the spirits of her dead babies to try to learn who or what killed them.  She assumes that such a thing is possible as well as that witches are actually responsible for the deaths of her seven babies.  Her husband even claims, "There is a murdering witch among us, bound to keep herself in the dark."  Even the most respected of these people believe that witches exist and pose an immediate and serious threat to their well-being.