Onne, why do you assume that the faith of Christians or, by implication, other faiths, is so offensive to unbelievers? As an atheist, I don't find Christianity offensive; irrational, misguided and naive, yes. Offensive only when some arrogant, smug, holier-than-thou Christian attempts to ram his piety down my throat.

The Golden Rule says it all; it's rational, moral, makes perfect sense and no higher being is required to act upon it.