Yoga Sutras of Patanjali translated by Yogi Kalinath - Chapter 2, Verse 21
Pada 2, Sutra 21
Tad-artha eva drshyasyaatmaa
The existence of the seen is only for the purpose of the Seer.
The Seer is the only constant and the seen, the manifested Universe, Nature is there both as the transcendental medium for the self to realize the Self Within distinguishing between the Perennial and the ephemeral, and as the ever changing landscape and medium for change purely for the enjoyment of the Self as the Witnessing Consciousness. Any other perception or understanding is simply nescience on behalf of the self, the projected Maya of the illusory self.
Self-Realization, realizing the Self Within as the True Self and not the conditioned self is the true purpose of taking incarnation as a human being. Everything else is secondary, at the very best an expression of That (Self Within) or at its most illusory purely a victim of circumstances.