Most humans believe in an idea that the first human began good elsewhere. Then there were two. Observation, thoughts, ideas began revolving. In an adventurous moment bad existed. Soon afterwards playful moments led to adventure bad. Hence, on this Earth, human settle began with good and bad.
Ever since, both good and bad existed. Can you mention, with proof, any single moment of human existence when one existed without the other.
Millenniums passed, good and bad lived happily, sadly ever after.
Then came equality. An opportunity for standing side by side in most aspects of social life. Would this affect good and bad? If we weigh these aspects, then a balanced scale means both need to coexist equally. At the same time, yet having no proof of either existing alone, this world may end having both laughing at us. Yes, laughing at us for trying to eliminate one or the other and not succeeding.
Life is a game of this and that. In every game, there is winning and losing. Life is a well planned strategy where there is a beginning and an end. A game of good and bad. Hence It all depends on how well we play.