Do We Have Good Grounds for Denying a Doctrine?

Protestants can't uniformly answer this question about what is and is not essential, because the bible itself say that. Doctor ortland divides up these doctrines and says the most important ones in the christian faith are essential, or first rank. He writes if some one knowingly and persistently denies a first rank tenet, we can have no confidence of that person's salvation. And this includes doctrines that aren't immediately related to our salvation.