My general rule for myself in life is: try not to be an arsehat. Or, if you discover you have been an arsehat/realise you're acting like an arsehat, acknowledge it (and, hopefully, if you're feeling brave and strong, apologise.)
I've fucked up in the past, I'll no doubt fuck up in the future and I take responsibility for those errors.
I seem to constantly encounter people who don't care about the harm they cause, and it vexes me.
I'm not Christian, but that whole 'do unto others' thing makes perfect sense to me, as selfish a dictum it may be (here's a thought: why not be kind because you can? ETA: here's another thought: try not to be extra facetious when making a point with a tenet you clearly believe in.) I would rather people not punch me in the neck, ergo I don't punch people in the neck --- even though there have been times I've really, really been tempted.
Is it so hard to live your life with a basic regard for others?