Why did the people believe in witches in shakespeare times?

The attitudes of people of Shakespeare's day toward witches were inconsistent. The fundamentalist Puritans believed very strongly in the existence and power of witches (hence what happened at Salem) but many people if not most did not believe in them at all, and considered them to be a bit of a joke. As a result, in plays like Thomas Middleton's The Witch, they are portrayed as silly and funny. Two songs from this play were incorporated into Shakespeare's play, showing that the witches were not shown as powerful or dangerous at all when the play was first performed.