first we must figure out what bad and good even means before we go on this whole discussion. my belief is that 'good' and 'bad' are strictly human things, or at least only restricted to certain species instead of being a universal thing. we have the capability to understand and dissect morals, wether or not this is instinctive or taught depends on what we're talking about SPECIFICALLY and can be debatable. however, they're so saying wether or not a species on another planet or in another universe will be able to comprehend this, or understand it in the way that we do. morals as a whole can be interpereted, and can be debated, and therefore i do not think it is a universal truth.
HOWEVER. i DO think that positivity and negativity are universal things. i mean up and down, left and right, positive and negative attraction, they all definitely exist. and of all of these things, we need BALANCE. we've established that god does not necessarily dictate everyone's entire lives and throws hurdles at them as a sort of test, so why do bad things happen to good people? for BALANCE. in nature literally everything seeks balance in some way, balance is the holding force keeping our entire solar system together like. JEEZ. it rains and it shines, without one or the other things would go horribly. so i think that yes we do need bad things in order to have good things too. this is why i hate the concept of heaven and hell. how someone acts in 80 years or so in no WAY makes it reasonable to sentence them to an eternity of suffering, or of good things. i have always said that if there was a heaven, or a hell, i would not want to go to either. why??? why don't you want good things??? i don't WANT an eternity of good or bad, there must be balance. that sort of fate defeats the whole purpose of throwing us on earth anyway, like we have learnt NOTHING. once i die, i want to stay there, i want my body to rot, and lucky for me that's what's gonna happen in my eyes :P
but what about evil? this is more of a philosophical thing over a spiritual/religious thing, but no i don't think instinctively evil people exist. and YES believe me i know, i've met my fair share of sick, 'evil' individuals, but i wouldn't say that they were birthed as an evil being, because the soul does not carry any sort of burden. the universe, as a whole, is warmth, it isn't good nor bad, but rather that balance that we seek comfort in. it is the choice of the individual whether they will lean towards positivity, or negativity. the mind itself is the source of these things like evil. abnormalities in the brain that can cause disfunction, troubled upbringing, these things can really shape a person, and writing them of as evil just doesn't cut it for me. there is good and bad in this world yes, but there is really no EVIL. there is envy, greed, gluttony. no real evil. there are still sick bastards who deserve to suffer but you know. people do evil things but there's no evil people.
but we can get REALLY deep into it and ask, well if there is no eternal consequence, why do we lean towards good? why is that the goal? really, we don't. we all have done bad things, we all do bad things, and we will certainly continue to do bad things. we lean towards positivity and seek that out because it's a natural thing. a warm blanket and a cup of hot chocolate is more desirable than being victim in a saw movie (provided you're not lactose intolerant or a huge fan of the saw series). but not all people seek happiness. some people really like being in the dark, and that's okay, sometimes nothing can change their mind. really what else can change their mind but their own mind...?? but to you i would preach good things, why? because in the balance and in the swarm of the good and the bad, with patience you will find comfort in the bad things too, the awful terrible things, and only then will you be at peace.