Ahh, more than just an illusion: manifestation on another level: in matter, in individuality. I believe there's nothing less about this reality, although it is most definitely not "all there is". But through this limitation in form comes a unique opportunity of experience and perception. To be gathered, harvested, recycled, added to the continuum, perhaps.
As we as individuals confined to our physical form may long for the boundless freedom of unity in spirit, so unity may long for the confinement of material individuality. To feel rain on your skin, to see the colours of dawn, experience the physical longings, cravings, allures of the senses to name some. If there would be no drive from one to other, there would be no creation or cycle, only static singularity.
erm, one of my thoughts on the univers budding
, I'm not that good with words