What Am I?

I am death,
Yet I am also life.
I bring pain,
But also joy.
I am war-mongering,
But I enjoy peace.
I am foolish,
But I am brilliant.
I am capable of great hatred,
and also of great love.
I will bring us all death,
Yet, Ironically, I gave us all life.
What am I?
I am a man.