In the same book he writes, "Is Christ divided?" Then he goes point by point to deal with the division. You may consider division neccesary, but it is never good. In this case, I do not even think that it was neccesary.
We should distinguish between the cause of or source of divisions and the surfacing of the division. In a perfect world I suppose we would all have unity, or at least much more than we have now. But we do have disunity and, for sake of argument, this is due to sin. In this sense, I agree that the fact of disunity or division is never a good thing. But this should be distinguished between the discussion of (or manifestation of) disunity (or the catalyst that causes the disunity to surface).
Consider Peter and Paul, for instance. Peter was separating himself from the Gentiles during their meals. Apparently everyone was willing to go along with Peter. So there was some degree of unity, right? Peter and the rest of the Jews and even Barnabas were all unified in their separation and for all we know the Gentiles didn’t make a stink about it either. We don’t know that they protested this and it seems doubtful that they would have. But Paul came along and confronted Peter, he opposed him.
Did Paul cause disunity (and, hence, a bad thing)? Or would you rather say that there was already disunity—disunity from the truth of the gospel—and all Paul did was bring it to light? I would go with the latter. What Paul did wasn’t a bad thing, even though it may have caused disunity to surface that lay hidden.
This leads to my first major point: Arriving at true unity sometimes means that we have to face our disagreements and let the division surface in order to hammer it out, if at all possible. Christ isn’t divided, but we often are and pretending like we aren’t isn’t going to solve the problem.
Now, one may object to this “But the Peter and Paul thing was over a very important issue: the gospel. Isn’t it better to let most of our disagreements lie dormant if they are not essential?” Well, for one thing, this gets complicated because not everyone agrees on the essentials and non-essentials. VW, for example, thinks he has “good reason” to be upset over what I said in this forum because it detracts from the gospel (post #61). I disagree that I’m doing that, but how else are we going to deal with it? Should VW ignore his convictions in this instance and, if so, when should he ever not ignore his conviction that a teaching perverts the gospel? So even if it is true that we should let non-essential lie dormant, that doesn’t necessarily apply in this case where there seems to be a disagreement as to how essential a claim or teaching is.
To address the question itself, I would say that we can’t necessarily know ahead of time whether we should discuss our disagreements over non-essentials or ignore them. I have a brother who thinks that we should keep the Sabbath just like the Jews did in the OT. I happen to disagree with him. In a sense, we have disunity here. Whether we ignore it or not doesn’t change the fact that we have disunity and division over this topic. Should we discuss it or not? Well if we discuss it and one of us gets angry then
it’s not the discussion that is causing division; rather, pride or some other thing is causing division. So not discussing our disagreement may give us some level of unity, but it doesn’t actually solve any problems. I may still have a pride problem that would cause me to get angry if my brother challenged me and I still have the problem that I disagree with my brother.
This leads to my second major point: Debate and discussion is rarely the cause of disunity and division. Attacking the debate or the discussion for causing disunity is often like attacking a pill that causes your cancer symptoms to surface. You may be able to have a degree of bliss in your ignorance of having cancer, but you have it all the same.
Finally, in anticipation of one more objection: yes, we should avoid foolish controversies about the law (Titus 3:9). But we can’t just automatically label any controversy that we want to be foolish and then appeal to Titus 3:9 to justify it. For example, I can’t just say “debates about the deity of Christ are foolish quarreling so no one should discuss it” and then appeal to Titus 3:9 to justify the idea that no one should discuss it. That such a use of Titus 3:9 is illegitimate could be called obvious from the fact that the deity of Christ isn’t related to questions about the law. But Paul also doesn’t say every question about the law is foolish. In fact, he spends a good amount of time discussing questions about the law in his epistles. He has in mind a certain group of people, Judaizers, raising certain questions. This is clear in Titus 3:9 itself and also 1:10-16. The Judaizers were apparently causing quarrels about things relating to genealogies and Jewish myths, among other things.