Yesterday, I asked readers if the Church of Latter-Day Saints is heretical. Brian of The Faithful Skeptic commented:
I'd argue that the average joe and jane methodist/presbyterian/episcopal/catholic, etc. probably don't have a thorough understanding of their church's theology either.
I'd agree that mormon theology sounds downright wacky. But then sometimes I think the only difference between catholics and mormons is that the catholics had the good sense to stop making stuff up 1500 years ago.
But aside from all of the theology, I know a lot of mormons. And at the risk of stereotyping them, they tend to be very good, caring, hardworking and honest people that truly love God and frankly do a lot more to embody Christian love than many other Christians.
That being said, I don't have a lot of enthusiasm for deciding whether they are heretics or not. While Joseph Smith was probably a total kook, most of his followers today are not. I think God probably has room for them too.
Emphasis added. I can understand that an excessive focus on doctrinal purity can hinder the mission of the people of God, but defending correct doctrine from false matters at some level.
Given the massive amount of text in the New Testament devoted to the importance of identifying and combating heresy, particularly the epistolary writers, either calling out heretical ideas and practices matters, or the NT writers were wrong.
As for the specific errors of the LDS, I suggest this handy brief from the Watchman Fellowship.
Now, to the harder matter: differentiating varying opinions from heresy. How do we say that a certain view is a minor error which God will not hold against the believer (e.g. Calvinist soteriology), and another is one that will result in damnation (e.g. Mormon anthropology)?
What is heresy as an evaluative criterion?