When it comes to practicing apologetics, that is, having cogent, logic discussions in the defense of the Faith, both sides must bring to the table certain requirements. Willingness to listen and openness to learning something new, whether it is a new point of view or a previously unstated assumption that helps move the discussion along. One can never lose sight of charity or love for the other as the goal is to bring each other closer to the truth, not to simply win a debate (although debating skills are very helpful).
Prior to any of this is the acknowledgment that there is truth at all. The trouble these days is that people treat objective truth itself as a negotiated fact such that “what is right for you might not be right for me” and in doing so hope to avoid any contention and allow each other to live in peace. But there is no peace in relativism. Truth cries out to be heard. God made the world as a single objective reality to be shared by all. Sharing our encounters with the world with others brings us closer and creates communion. The more we reduce the world to our own private perceptions the more we pull away from each other and create disunity. Taken to its extremes, the powerful subjugate the less powerful with one perception over another. When discussing pro-life and social justice issues in general, there is a consistent thread of the vulnerable being exploited or neglected due to an opinion that some people are less important than others.
Once somebody claims that there is no objective truth, they are already claiming an objective truth. To live in such a contradiction is neither freeing nor fulfilling. The reversal of the “dictatorship of relativism” has been one theme of the current papacy and it behooves us to properly equip ourselves in dispelling this illusion.
Some great starting points:
Making Choices by Peter Kreeft
The Godless Delusion by Pat Madrid
Disorientation by Various Authors
An Invitation to Faith by Benedict XVI