The purpose of existence can be relative. For me its an opportunity to grow. I took birth for some reasons that will enable my soul to grow. The ultimate goal of my soul is to realize nonduality. How and when is what life/existence will teach me.
Hence I start from a dual world and find my way back to where I came from - Pure awareness. This makes complete sense to me as to why one is born with ego and why the world has been created with dual nature.
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From Form to Formlessness