"Love your enemies." I& #39;m about 99.99% sure insulting those we disagree with plays into Satan& #39;s hands and displays our lack of "peacemakers" calling and purpose God gives us.
What is your goal in addressing the false teacher? Insulting them, sinful as it is, really doesn& #39;t help anyone but people who already agree with you. Not many followers will tune in to an insult, instead they& #39;ll be defensive and reject you outright.
Our goal should be to win those under them to Christ and true worship. Perhaps a better way is to express the truth in kindness and pray the Spirit would open their eyes. It& #39;s harder work, but more in line with 2 Tim. 2:24-26 :)
btw, insulting them encourages a sinful attitude in those we lead as many pick up that it& #39;s acceptable to insult others. But how is that in line with 2 Tim 2:24-26, Matt 5:9, and Matt 5:44 (love your enemies).