Hello, we're here to help you.
Usually the person or group of people were once very close to you or had similar views to yourself or you just accepted them for them and they didn't accept you for you..
So you've been severed from a group, your family or a close friend? What can you possibly do to salvage your relationship? In our experience it's best for you to reflect and look at the situation from as many points of view as possible so that you can really understand where they are coming from and decide where the true faults are. Time also heals all wounds and it's certainly a smart move to give them some time ot think and calm the situation.
Making amends is never usually that simple mainly due to the level of prior conflict, we recommend taking it slowly but surely so things start to fall back into place.
Work RelatedWork related are likely the worst types of severence, whether that would be you leaving an awesome company with lots of friends and then fell out of the work circle loop (I personally experienced when I worked for a company called Maid2Clean, the staff were very friendly to the point I talked to some of my colleagues more than my family before and after work but after I left it felt harder to relate to one another and so I kind of slipped away in a sense) it takes a stronger person than myself to be able to discuss things with friends while not really understanding where they are coming from. Luckily I found some other great friends when I started working at a nearby school so not so bad at all! Life is too short to brood.
I hope my ramblings help you make your decisions and that everything goes well for you!