John is fairly open about his feelings for Parris. In the first act, he gets into arguments with Parris, and some of his feelings come out. One issue he has with Parris is his preaching style. Of it, Proctor states, "I have trouble enough without I come five mile to hear him preach only hellfire and bloody damnation...there are many others who stay away from church tese days because you hardly ever mention God anymore." So, he feels that Parris' preaching style is much too intense, negative, and critical. Proctor also feels that Parris is unusually worldy and materialistic. When Parris demands to outright own the house that the church provides for him, Proctor says, "to ask ownership is like you shall own the meeting house itself," voicing his dismay that a preacher would need that ownership. In act two he adds to his opinion of Parris' materialism by mentioning of Parris that "for twenty week he preach nothin' but golden candlesticks until he had them." He feels that Parris is a petty, negative man, and he "sees no light ofgod in that man." He feels so strongly that Parris isn't a good minister that he jokingly says that he is going to "find and join" the faction or party that is forming against Parris, and, his youngest son isn't baptized because John doesn't want Parris to "lay his hand upon my baby."
I hope that gives you a feel for how John feels about Parris; it certainly isn't warm and fuzzy, and John has no qualms expressing it.