If you do not take the distinction between good and bad very seriously, then it is easy to say that anything you find in this world is a part of God. But, of course, if you think some things really bad, and God really good, then you cannot talk like that. You must believe that God is separate from the world and that some of the things we see in it are contrary to His will.
Confronted with a cancer or a slum the Pantheist can say, ‘If you could only see it from the divine point of view, you would realise that this also is God.’ The Christian replies, ‘Don’t talk damned nonsense.’ For Christianity is a fighting religion. It thinks God made the world—that space and time, heat and cold, and all the colours and tastes, and all the animals and vegetables, are things that God ‘made up out of His head’ as a man makes up a story.
But it also thinks that a great many things have gone wrong with the world that God made and that God insists, and insists very loudly, on our putting them right again.
From Mere Christianity by C S Lewis