I have two concerns/questions about the original post:

1. Who gets to authoritatively decide what is "sound Biblical Doctrine"?

2. Isn't the implication of the original post that if two Christians are not in 100% agreement with each other doctrinally AND they are not in 100% agreement with sound Biblical doctrine (i.e. rather than just what they may mistakenly think sound Biblical doctrine is), isn't at least one of them a "heretick"?