Christian author Tim Muehlhoff says believers need to "yield to God's power from outside" themselves in order to communicate in a civil, Christlike manner.
Christianity Today has published a Q&A with Muehlhoff regarding his book, I Beg to Differ: Navigating Difficult Conversations with Truth and Love (InterVarsity Press, 2014).
Muehlhoff says that "in the heat of the moment" of a conversation a Christian should remember the advice of A.W. Tozer. "You shall receive power, a potent force from another world invading your life by your consent, getting to the roots of your life and transforming you into someone like Christ." Muehlhoff says the discipline to yield to God's power from outside "needs to be in place before the conflict actually happens," and that comes through practice.
In addition to seeking God's help, Muehlhoff offered some pointers. For a conversation to "make progress, you need to acknowledge the other person's emotions. It doesn't mean you agree with what they're saying, but you need to acknowledge that he or she is upset or passionate. If you don't, there will be a roadblock in the conversation."
Also, a good strategy is to "emphasize points of agreement" or state a "willingness to consider a different point of view." The result will be that the other person will "begin to mirror that attitude back."