He's been posting some excerpts on his blog, and today he shares some of Ligon Duncan's insights.
His answer is worth reading several times over:
When engaged in polemics it does not take too long before strong words can be spoken against your character. The great New Testament scholar Gresham Machen was often vilified and subject to personal attacks. Why does this happen and how should you handle it?Read more here.
Expect it. Those who teach aberrant doctrine successfully are always, always possessed of two qualities – pride and intelligence. Both of these will often feature in their defense against critiques of their work.
Be determined to know their view (and to be able to articulate it) better than they know it themselves. If you cannot to state the position of your opponent, in your own words, in a way in which they can recognize themselves, then you do not yet understand your opponent’s position and you are not yet ready to enter into polemics with it. Following this counsel would, by the way, cut out 99% of theological discussion on the internet!
Refuse to take the insults thrown back at you personally. You are a servant of the word. And if a servant, you must be prepared to be treated like a servant. The only thing that matters is the glory of God, the vindication of the word, the upholding of the truth, the faithful proclamation of the Gospel and the good of souls. Let them cast what aspersions they may. You only crave the affirmation of One.