Growth is good ... to a point. It's good that children grow into adults, but what would happen if they didn't stop growing?
What happens when body cells continue to grow? It's called cancer, and unless it's stopped dead, it kills you.
We live on a finite planet, but for several centuries human population has grown exponentially, human consumption has grown exponentially, and human activity has grown exponentially. Such growth can only continue for so long. And then what happens?
Arithmetic, Population and Energy: Sustainability 101