I think it was just a sign of the times for that era. The fundamental belief of the time, that God was supreme and he was opposed by the Devil was a universal thought. Every good guy needs a bad guy. They believed in the existence of the Devil in everyday life and guarded against it. The Witch Trials while pretending to be about witch craft was really about the power of suggestion and greedy people that coveted others land.
The Salem witch trials were by far the biggest witch trials ever held in the American colonies. Prior to the Salme trials there had only been about 80 defendents in witch trials altogether in America, of whom 16 were hanged. About 140 people were arrested in the Salem trials, and 20 were put to death (another 4 died in prison of disease). The scale of the Salem trials makes them unique in American history.
while it is possible (as an answer above suggests) that greed for land migh thave had something to do with some of the accusations in the Salem trials, this was only a small part of the story. Tensions in New england brought about by political upheavel in England, the war between the english and the French and the Indians, and the prolonged absence of the governor, helped to create the sort of tense social situation inwhich witchcraft accusations were most likely to occur. The sermons preached by Samuel Parris, a minister of Salem, helped to foster the idea of witchcraft as a cause of the ills that beset the colony, and the trails were encouraged by Increase and Cotton Mather, who had had experience of large-scale witch trials in Europe.