Very little that someone else does in their life is going to affect the rest of us, so "live and let live."

Oh, if only people would take that to heart. I'm not a religious person, but along with that idiom, I also wish people would practice "Do unto others..." If both of those sayings were put into practice, practically every ill caused by humans would cease to be.

Edited to add: Especially those ills created by those who claim to be religious!