Ironically, the behavior you describe is immoral in my view. I also am a religious person, and I also don't believe in bending morals or that talk will heal all disagreements. However, with political opinions, the primary reason otherwise well intentioned people support bad things is that they don't understand that they are bad. Shunning someone actively makes that situation worse. Sure you can't win people over by arguments, but you can influence them gradually, and if they are your friends, you should want to do that for their own good.