Black and white
Evil and good,
The 2 sides of
The same coin.
One cannot exist without the other
Because without one
The other would
Lose its value.

Angel and Devil
One makes the other.
If there was no Devil
Would anyone consider
The angel good?!
The Devil's presence is what makes
The presence of an Angel important.

If there was no sadness
Would people ever
Value happiness.

So,
Black and white
Evil and good
The 2 sides of the same coin.