How do i start my introduction for "Conflict can divide and unite the people who encounter it?" linking to to the Crucible
and how does Conflict divide
The Putnam’s and Giles Corey?
Marry Warren and Abigail?
Mary Warren and Abigail are not particularly close friends at the beginning, and their relationship is not equal (Abigail is by far the stronger of the two). However, they are united in their fear of getting trouble and being punished (the conflict). They're united throughout the trial, as well--until Mary is confronted by an infuriated John Proctor and convinced she needs to do the right thing. When shedoes call out the girls' deception, Mary is in direct conflict with Abigail. You can take it from there.
The Putnams and Giles were never united; they were always in conflict. However, Giles is in good company, since the Putnams are in conflict with everyone who has a mind and a mouth and uses them. In the play, only Hale and Parris are in their good graces (because Parris is obsequious and fawning, and because Hale can help them get what they want). You know how their story goes, so do write what you know.
In terms of starting your essay, I might think of some real-life scenarios to begin with, perhaps war, for example. The conflict of war both unites like-minded countries and people but can also cause the deadliest of conflicts. (Think Civil War as something pretty familiar.) Starting with the big picture, so to speak, allows you to dramatize your picture of conflict, dividing, and uniting then funnel down to your specific Crucible-related thesis. Have fun!