I think this falls under 'the road to hell is paved with good intentions'. That's an easy statement to make. How do you know that your well-intentioned crusade

I think this falls under 'the road to hell is paved with good intentions'. That's an easy statement to make. How do you know that your well-intentioned crusade doesn't cause more harm than good? Historically, I've found that self-righteous crusades cause a lot more problems than they solve.