So does that mean that when someone shows up on your Blog and goes flying off the handle, that that is somehow a gift? No. But if you can keep the discussion civil, by responding respectfully, passionate emotions may settle down, and their critical review will bring focus to the debate.
For instance, most Calvinists are aware that the 5-Points of the TULIP system did not originate from John Calvin, but from the Calvinist response to the Arminian Remonstrance. The point is that godly, wholesome debate can bring deeper understanding of the issues, and sculpt arguments like a bodybuilder sculpts muscle.
Some pointers that I've learned from debating Calvinism vs Arminianism are these:
1) Keep it simple. Stick to a few points at a time, and be economical with your word count. Realize that posting encyclopedias will never foster an effective dialogue.
2) Do not attempt to slowly build your arguments. Use probing questions to immediately get right to the heart of the issue.