The list below contains what Durham regarded as the top 5 major theological errors if we judge by volume of references in his writing/strength of his language when mentioned (not in descending order):
They were “the enemies of Christ’s satisfaction,” “blasphemers” and “wretched.” Indeed so far had they sunk into error that they “are not worthy to be disputed with, nor accounted Christians; but rather to be joined with, and reckoned among, Heathens, or the followers of Mahomet…”
Arminians were the “enemies of grace” who made conversion dependent not of the sovereignty of God but “on man’s fee will.” Durham felt it was easy to demonstrate “how dangerous and damnable this error is.” Arminians indeed deserved to be listed among “’the most gross heretics of old and of late.” Durham’s opposition to Arminianism arose in part from his belief that Arminian tenets “overthrow the design of grace in the salvation of sinners.”
To cite just two examples:
“… that blasphemous conceit and fancy of the Papists, who account their abominable Mass a propitiatory sacrifice … which … is most horrid blasphemy…”
“… nothing doth more natively breed anxiety and spiritual torment than the principles contained in the Popish Doctrine…”
In some respects an opposite error to Popery, “…the Antinomians … make all sanctification to be justification … the Papists make all justification to be sanctification; therefore we would learn to distinguish these two, yet not so as to separate them.” They get particluar criticism each time Durham broaches their view of justification.
Particulary “that foolery of Quakers.” They didn’t hold back in their polemics in these days!