The overture is introducing The Crucible to the reader. It starts out with Rev. Parris whose daughter is unexpectedly ill and rumors that she is "filled with the devil" start bubbling to the surface. Paris refuses to accept the rumor of witchcraft in fear of ruining his reputation. However, Paris did not have a good reputation to begin with. He felt that he was being persecuted wherever he went, didn't take much of an interest in children, and he would feel insulted if someone would get up to shut the door without asking permission.
The people of Salem were very religious. They rejected theaters and novels, which were considered acts of vanity, they do not celebrate Christmas, and they spend their holidays praying to God. What I don't quite understand is that how can people so religious easily kill human beings (some may even be with child) based on false accusations. This presents a flaw in their society, they are to worried about themselves to take a minute and think about what they are actually doing. The people are in hysteria about witchcraft and this evil. This clearly illustrates the beliefs of the puritans at this time.