My advice to people of faith is when your clergyman starts the social justice bs walk. There are plenty of other congregations. Marxism has no place in a house of worship. Put the clergy on notice that their failure to stick to the scripture is the reason for your departure a
When one goes to a house of worship one has a reasonable expectation of hearing actual religious content. The far left political stuff usually packaged under the communist code word social justice has no place in a legitimate Service. All of us have jobs to do and when your clergyman delves into social justice he has failed to do the job he was hired to perform.
In general a walkout with no explanations is sufficient. When I did this in VT, the outraged Rabbi demanded an apology. He then tried to negotiate a face saving ploy where I would return and make up an emergency. In truth I figured most would think I went to the bathroom. Apparently my departure mid sermon was noticed. I also was not around to be introduced to the locals.
Most people are afraid of clergy. When they do their job they deserve respect. However, once they venture into Marxism ditch them.
You do not owe an explanation for your actions. Just keep going because you are going to subjected to word games and twisting of scripture. Social justice and progressivism are code words for communism. Communists are never honest about who and what they are. They are full of lies code words and rationalizations for their crimes against humanity.
Sorry but a Communist in the 20's might get a pass as a dreamer. The crimes and failures of communism are quite apparent to any honest observer.