When we try to communicate, something is always lost in the process. Even if we speak the same language, the process of thought to speech to hearing to comprehension is rife with landmines of misunderstanding. Each step compromises on the previous until what is comprehended by the listener is seldom exactly what was conceived by the speaker.
This problem is compounded in written communication. Where face-to-face conversation depends much on subtle and no-so-subtle body and facial expression, the written word has no such ability. True, a person's written vocabulary is typically three to five times larger than their spoken, but this hardly makes up for the cultural and social equities the physical gestures, facial cues, and odd vocal tones which are often critical to the meaning of the thought being expressed.
Too often, the listener is more interested in formulating what they have to say than to hear what is being said by the speaker. This sets up an insurmountable obstacle to understanding and inevitably leads to problems in communicating. It is critical, before beginning and conversation concerning a subject that could be considered controversial, to first define fundamental terms in a way both parties agree. A groundwork must be laid before the structure of the conversation can even be framed. Without that groundwork, no exchange of ideas is possible. What results is a mere confrontation of ideas that probably have no bearing on either speaker's point.
Semantics -- "the meaning of a word, phrase, sentence, or text." It isn't just a term to read about in passing. It is a term to consider as critical to effective communication.
To discuss politics, religion, or social issues, one must first come to an understanding of what the terms being used by both speakers mean to each of them. One person's definition of religion is probably different than another's. It is almost certain that one person's definition of abortion is different from another's. Unless the difference is first identified and recognized, there is little point to debate. Conversation then becomes argument, and argument leads no one to understanding.
Define. Listen. Question and inquire to understand. The exchange of ideas can be very rewarding and enlightening, but first you must understand the difference between definition and interpretation.