There is no doubt that the idea of one Absolute that has no real connection to or involvement with the manifestation of life in the world; and which thereby treats that existence as an illusion or something less real, has strong historical basis in human history and is the underlying force between many spiritual paths that preach abandonment of the world for the greater Truth of the Spirit. This may be found throughout the world, and underpins the monastic ideal.
Sri Aurobindo points out that despite this long historical direction of human thought and focus, the illusionist approach is neither necessary nor inevitable; and has some serious limitations if we examine the nature of Reality more closely.
He explains: “The idea of an essentially unreal universe manifested somehow by an inexplicable Power of illusion, the Absolute Brahman regarding it not or aloof and not affecting it even as it is unaffected by it, is at bottom a carrying over, an imposing or imputation…of an incapacity of our mental consciousness to That so as to limit it. Our mental consciousness, when it passes beyond its limits, loses its own way and means of knowledge and tends towards inactivity or cessation; it loses at the same time or tends to have no further hold on its former contents, no continuing conception of the reality of that which once was toit all that was real: we impute to absolute Parabrahman, conceived as non-manifest for ever, a corresponding inability or separation or aloofness from what has become or seems now to us unreal; it must, like our mind in its cessation or self-extinction, be by its very nature of pure absoluteness void of all connection with this world of apparent manifestation, incapable of any supporting cognition or dynamic maintenance of it that gives it a reality,–or, if there is such a cognition, it must be of the nature of an Is that is not, a magical Maya. But there is no binding reason to suppose that this chasm must exist; what our relative human consciousness is or is not capable of, is no test or standard of an absolute capacity; its conceptions cannot be applied to an absolute self-awareness: what is necessary for our mental ignorance in order to escape from itself cannot be the necessity of the Absolute which has no need of self-escape and no reason for refusing to cognise whatever is to it cognisable.”
Sri Aurobindo, The Life Divine, Book 2, Part 2, Chapter 15, Reality and the Integral Knowledge