80% of humans are most comfortable dealing with things the way they've always been dealt with, and worrying about how things make people feel rather than objective truth (source:The Myers & Briggs Foundation).
If you understand this, the next intuitive leap is to understand that you can't change anyone's minds by rationality (source: The Backfire Effect) . All you can do is live your example, and stand by your principles. Calmly rebuke friends/family (if you can do so politely, and preferably in private) who violate your principles. When people begin to see you being happier, or more successful doing it your way, a small change in the circle around you will begin. It will then spread like raindrops in a pond, until it becomes (as a society) more convenient to change than to stay the same.
It is a long process - generational, even. However, you can witness its progress in things like gay rights, a winding down of racism, etc.