John Proctor's major complaint against Parris's sermons is that he preaches too much about hell and the eternal damnation of the people of Salem. In addition, Proctor does not accept Parris' greed -- Proctor tells Rev. Hale that Parris preached for months about getting golden candlesticks on his alter until he finally got them because the pewter ones that he originally had (made by Francis Nurse) were not good enough for him. In addition to having an argument with Parris, Proctor also dislikes Putnam because he thinks that he owns all the land in Salem and argues with Proctor over it in Act 1.
At various points in the novel, Proctor reiterates his opinion that he does not see the "light of God" in Parris. Particularly during this time frame, ministers were thought to have near-supernatural connections with the almighty, and Proctor feels that Parris is not as connected with God as he should be.
His complaint against Parris's sermons is that they smack of greed and corruption. He points specifically to his constant railings about damnation and brimstone, and also asserts that he has preached about worldly gains like the golden candlesticks he wanted just so that he could get them.
The character of a corrupt minister is not confined to The Crucible, however. Throughout history, from stories like "The Minister's Black Veil" all the way to the present, we are shown preachers, priests, Levites, and religious figures who, for one reason or another, are of questionable character.
Proctor also argues with Putnam and other church members during this story as he attempts to defend women accused of witchcraft.