Parris is the minister of Salem, and he is a powerful and respected figure in the community. He is also a very proud and ambitious man, and he is jealous of anyone who threatens his power or position.
John Proctor is a wealthy and respected farmer, and he is also a very independent man. He is not afraid to speak his mind, and he is not afraid to challenge authority. This makes him a threat to Parris, who sees him as a potential rival.
Parris's jealousy of Proctor is evident in several scenes in the play. For example, in Act I, Parris accuses Proctor of witchcraft. This accusation is false, and it is clear that Parris is making it out of jealousy. He is also jealous of Proctor's relationship with Abigail Williams, who is Parris's niece.
Parris's jealousy of Proctor is a major factor in the play's conflict. It is one of the things that drives Parris to pursue the witchcraft trials, and it is also one of the things that leads to Proctor's downfall.