So the method is to each argue their case, and only then if it involves the set of "essential to salvation"? Would it be correct to say the differences of interpretation are settled by argument using the rules of reason?
I have never called it argue but more investigate the reason and foundations for why we believe what we believe. Not only those things essential to salvation because it’s interesting to support and back up what we believe on even the smaller things but then I am a person who enjoys a good debate. Others not so much. I firmly believe that for most people the simple gospel of “believe on the Lord Jesus and you will be saved – and your house” is about as far as they get in their life. As long as they are fervent in that belief I believe they are saved.
>>Would it be correct to say the differences of interpretation are settled by argument using the rules of reason?<<
Human reason seems to always be eliminated by revelation.