It seems pretty clear that the reason Reverend Parris has so many enemies in The Crucible by Arthur Miller is because he is looking for them. He spends a lot of his time either looking for a fight or whining that he is not being treated fairly. When he is not doing that, he is being suspicious of everyone around him.
Miller takes the time to describe Parris this way:
In history he cut a villainous path, and there is very little good to be said for him. He believed he was being persecuted wherever he went, despite his best efforts to win people and God to his side. In meeting, he felt insulted if someone rose to shut the door without first asking his permission.
In the first scene of the play, Parris is forced to admit that he saw the girls in the forest last night, which makes one wonder what he was doing there. Perhaps he was looking for more trouble.
When he and his niece, Abigail, talk privately, he is extremely agitated because he is worried about what this "sickness" his daughter Betty seems to have. He asks Abigail about her reputation in town, and then explains rather frantically that he has to know the truth about last night. He says,
[I]f you trafficked with spirits in the forest I must know it now, for surely my enemies will, and they will ruin me with it.
Of course he is referring to his congregation. He goes on to say that there is a "faction" and a "party" of his church which is determined to remove him from his position, and that may be true. He calls his own congregation "stiff-necked people," and surely if that is how he sees them and treats them, they must feel his animosity.
Later in this act, Parris gets in a contentious argument with John Proctor and Giles Corey over how much he is paid and how underappreciated he feels. The two men are unhappy with Parris because he preaches too much "hell and damnation" and talks much more often about money than anything else. Parris overestimates his worth and feels as if he should be given the deed to the house he is living in. He also believes his congregation owes him blind obedience:
There is either obedience or the church will burn like Hell is burning!
It is not surprising that Parris's arrogance and insecurity cause him to be edgy and suspicious of the very people he has been called to love. It is also not surprising that his "flock" does not regard Parris as a loving shepherd who has their best interests at heart--because he does not. He finds enemies because he is always looking for them.