Why would an infinite Oneness create a finite, fractured world? For the same reason that a musician forces himself within the confines of a small wooden box with strings. Or a poet within the rigid structure of a sonnet.
We dwell within a living work of art, perhaps a symphony, or perhaps a dance, of uncountable parts. If we look with open eyes, we will discover the signature of an unknowable Creator within the knowable patterns of nature.