Because there are are different kinds of unwholesome karma being
created... there are so many bad people in our world.. each of them
done different kinds of bad deeds. Our entire existence, our life,
everything is due to karma.
Just like animal kingdom... there are even more than 36 kinds of
animals. This is due to different kinds of ignorant and unwholesome
karma being created by their Body, Speech, Mind while they were
people like us.
Unwholesome karma leads to the 3 lower realms: Hell, Ghost, Animal
realm. Wholesome karma leads to 3 higher realms: Asura, Human, Deva
(celestial being/heaven) realm. All Buddhas teach this: Avoid evil,
do good, and PURIFY ONE'S MIND. Most religions emphasize 1) and 2),
but did not emphasize 3). Buddhism thinks this is particularly
important because our minds need to be purified of defilements and
afflictions before we can attain liberation from rebirth in samsara
(world of sufferings; the 6 realms).
an article i posted recently:
The Pursuit of Happiness, Bliss and understanding
Sufferings
