Facebook groups can be confrontational and leave people with a virtual predisposition in how they are going to treat you if and when they meet you in person. Choose the words you stand behind because that is where you are being placed when people see what you write before they meet you.

WRITE RIGHT or BE WRONGed

If your posts generally cut down, degrade, bully, and refuse to listen/reason - how are you going to appear to the reader? In these days of internet as FIRST meeting grounds, followed by meeting in person it matters how your words are written. Selecting your written words can be so much more difficult than speaking on the phone or in person. Realize certain words when seen create MORE response than when spoken. This is a matter of prejudice in what we are willing to view and find acceptable.

Images are said to convey thousands of messages - things that matter include placement and timing. Who is this message in front of and why? Take these observations down to the concept of written words - because these are still visual representation of concept. Modifiers to words (adjectives and adverbs) paint the subject differently in the mind.

WHAT DID I WRITE?

I've had situations that I posted a response and chose to remove it once I read the tone being used. Sometimes it is good to take an objective look at what is being said and your response as a broadcast message and if it isn't appropriate as a broadcast - take it one on one with the person. Some discussion is best held in person or over the phone, at least you then understand the inflection on the words used. It also takes the messages out of broadcast mode to a group that might not appreciate the exchange of words.

It is possible to agree to disagree and let it go, or work toward understanding.
Constructive criticism can be enlightening to the original poster and may result in changing your opinion once you engage in understanding.
Solution based responses to concerns stated are a great thing to see - they show you have someone interested in listening and being actively engaged in conversation.
Move goals forward when you post and respond. Opinions change over time and some in the group may be less willing to change, even fixed in their beliefs, while others are very flexible. Evolution of an idea usually requires being flexible and listening outside the labels and concerns that we prejudge in how we listen. Remember the addage - "A mind is like a parachute, it functions best when open".

PRE-WRITE and POST?

If your feathers get ruffled easily online, realize it and do something about it. Write the response to the side, read it over, confirm it is what you want to say, talk it over, then post it in.