Gillian Law pointed me to this essay by Roger Nicole on Polemic Theology, which in my view is another 'must read' for us young theologians. Here's an extract:
When we give due attention to what we owe those who differ and what we can learn from them, we may be less inclined to proceed in a hostile manner. Our hand will not so readily contract into a boxing fist, but will be extended as an instrument of friendship and help; our feet will not be used to bludgeon another, but will bring us closer to those who stand afar; our tongue will not lash out in bitterness and sarcasm, but will speak words of wisdom, grace and healing. (Proverbs 10:20, 21; 13:14; 15:1; 24; 26; 25:11; James 3)