Another answer to your question is that it's fundamentally misguided due to your assumption that good and evil are absolute concepts and that there can't exist separate and consistent moral worldviews. Consider the historical crusaders joining a brotherhood of Christ to save their holy land from the infidels and secure safe pilgrimages for millions of their fellow Christians, and then consider a Muslim warrior defending his homeland and family in the name of Allah from crazed zealots of an imperfect prophet. Who is good there? If you asked them, they'd both say they're the good one and the other is the evil one. They'd both say the reason they KNOW they're the good one is ultimately due to insight into the moral fabric of the universe granted to them by God (the same god, funnily enough). Ultimately, it's impossible to say absolutely which one is right without appealing to something like divine revelation.

Another assumption I think you should reconsider is your implied stance that good people are necessarily absolutists in their principles. You say the good people wouldn't use nuclear bombs, but why? Nuclear bombs have ushered humanity into the greatest and longest period of peace in human history. You say the good people would never use torture, but why? I agree with other commenters that for practical purposes torture is nearly always useless and inhumane, but suppose a hypothetical hemophobic (and Evil!) nuclear terrorist that you'd just need to barely cut (light torture!) and then he'd tell you the secrets to his dastardly plan to bomb an orphanage. Are you sure that a good person would be obligated to stand by as the orphans explode instead of giving that guy a pinprick? Suppose the "good person" sticks to their principles and lets the orphans dies, what should they do to the terrorist? This guy's really evil, he spits on puppies and doesn't even feel bad about it. You also know with 100% certainty that he'll never reform, Doctor Strange told you so. If so, wouldn't it be more moral to just kill him? Why waste resources on his useless imprisonment when it could be spent on thousands of mosquito nets saving thousands of nonevil lives from malaria? Also, why is he evil? Suppose it's even 1% likely that evilness spreads through genes, if the good guy knew that and let him have kids wouldn't it be partially the good guy's fault if his nuclear terrorist baby bombs another orphanage? Perhaps you have satisfying answers to all these questions, but if you don't you just justified the torture, killing, and eugenics-ing of "evil" people.

Ultimately, the impression I want to leave is that ethics are hard and complicated and most certainly more nuanced than a good and evil divide. There exist counter arguments to some of the things I said in this comment, but I'm guessing exploration of those counter arguments would leave you with a more nuanced view of good and evil regardless.