That is the thing. That is really up to you. I have been in a friendship where the friend constantly degraded me and insulted my wife regularly in private and to her face. Every once and a while I would stand up to him, but for the most part I was passive and let him and his wife push us around emotionally. What confused the issue is that they were helpful in other ways and were actually good friends if you put aside the stuff I wrote before.
Push come to shove, what eventually happened was I had enough with the emotional manipulation and I said get out. There is nothing wrong with standing up for yourself. I have always tried to see both sides of the coin, but when the other side of the coin refuses to compromise and meet in the middle despite every chance you give it you have to make a decision to say "No more. If you can't talk in a civil manner please leave my home."
Just to clarify, just because you have had enough does not justify being rude, hateful or vengeful. You are better than that and being any of those things just sinks you down to the level of that person or people. Stand up for yourself and hold your boundaries, but don't burn bridges. I don't see that friend and I reconciling because of what he has done and the money he stole from me doesn't help, but when people ask what happened, I am tactful but honest. I don't lie about the issue, but I do make sure there is no anger or hostility in my voice since all that does is make me look a fool.
On the other hand, if you are talking about saying enough is enough about life style for example, I have come to the same point about my health recently. Again, that is up to you. When you make any choice like this you must be 100%. Just be sure you are smart in any choice you make with people or life style.