how can an innocent man become a bad man

a man born innocent and clean
he could become a good man
he could become a bad man
but how can an innocent man become a bad man?
who is guilty?
the fellows?
the maker?
himself?

in the world of millions fellows
all were once innocent and clean
how possible for the perfect cleanness to become contaminated?
when was the first dirt took place?

and for what reasons shall the good maker introduce the badness to his invention?
and for what purposes it would serve?
and from his perfection why such flaw would happened?
or he is indeed not perfect
for if his creation is not perfect
isn't the maker responsible for that?
and if he can't correct it
would he be guilty?

or if he is indeed perfect
and the good and the bad are meant to mixed in harmony
that the badness is indeed compulsory for the existence of the goodness
why badness is considered bad though?

after all
are we being created?
or are we born free out of nothingness?
and how come nothingness is the origin of everything?