Whether the hells or heavenly realms are taken literally or metaphorically, the important thing to understand, in my view, is that all of our actions have consequences. Wholesome leads to wholesome and unwholesome leads to unwholesome. And as far as the spectrum of our actions reaches in both wholesome and unwholesome directions, so too do the results.
But if we are able to understand that all living beings are worthy of loving-kindness and compassion and we work hard to treat them accordingly, all the heaven/hell stuff will sort itself out just fine.
"To reach beyond fear and danger we must sharpen and widen our vision. We have to pierce through the deceptions that lull us into a comfortable complacency, to take a straight look down into the depths of our existence, without turning away uneasily or running after distractions." -- Bhikkhu Bodhi
"No man ever steps in the same river twice, for it's not the same river and he's not the same man." -- Heraclitus