Maybe this is a way to think about the question:
The main spiritual problem is Pride. Give a man enough pride, and it will sink him straight to hell.
So then, we can see that your hypothetical preacher could be doctrinally pure (at least anywhere any asks about). He can say all the right things, and have the correct, Reformed answer to all the questions. And at the end of the day, his knowledge won't avail him at the Judgment Seat. "But Lord, I did XYZ in your name, and all my sermons were letter-perfect." And the Lord will answer, "Depart from me, I never knew you." Mt.7:21-23.
The important thing is to know (and be known by) the Lord; which is to love him and to be willing to listen to him, and be corrected by his Word.
Everyone has his blindnesses. It's the ones who claim to be able to see perfectly that are MOST blind. Their guilt remains, Jn.9:41.
Maintaining error is never helpful, but its harm may be mitigated by what is good in one's theology. Now, it might be unusual in the extreme, but a prideful holding on to an erroneous doctrine of, say "footwashing," might lead a man to hell, because he made holding on to his formulation of that doctrine his own personal test for truth. "No one who disagrees with me can be saved." He's pretty much added to the gospel at that point, and is under Paul's anathemas, Gal.1.
What about your Methodist minister? His errors on assurance or perfectionism seem to be less crucial to the core doctrines of Christ and salvation. So, what he affirms seems to outweigh what he denies (as we would define true doctrine). That doesn't make his teaching other than dangerous, on those topics. But it does mean that we ought to be hopeful that his love for Christ and truth leads him into a saving embrace of the truth of Christ in his doctrine--even while he continues to hold and to teach in certain ways that are not compatible with his best affirmations. The Lord is able to make him stand, Rom.14:4.
The worst consequence of bad teaching is not that pastors continue in their own errors, but that their sheep are fed an inadequate, or unstable, or mixed (etc.) diet. The receiver of contradictory "truth" may have a different sort of experience than his pastor or another pew-sitter, trying to reconcile one bit of his pastor's theology with another. Confusion leads to uncertainty, and perhaps an actual failure to grasp hold of the Christ-who-saves. Such a pastor may keenly feel he's not one to attain perfection, ever. But if he teaches that it iIS attainable, he may send one of the sheep into a terrible blind-alley of self-righteousness. He bears the blame for that, Ezk.3:18.
Back to the strict Calvinist preacher. His motives may be horrible, for preaching, cf. Php.1:17-18. But the truth he preaches should actually help people hold onto the Christ-who-saves, even if he himself ends up a castaway. At the same time, it is hard to believe that over a long period of ministry, his hard-heart and pride won't ruin his ministry in some way or another--both for himself and for many of his hearers; or have the worst lasting effects on the rising generation.
Pride keeps people from the truth, and maintained in and maintaining their errors. Thank God not all of it is as bad as it could be, both for the shepherd and for the sheep. Grace preserves and defends, even when we are not all that we should be.
Hope this is helpful.
Hello fellow PBers!
