If Brahman is ultimately the universe it manifests and unmanifests or a God creates Brahman and destroys or dissolves it. But matter cannot be created nor destroyed. So Brahman must be everlasting. Brahman cannot be in maniefest and unmanifest forms. A Creator would be required for Brahman's manifestation.
This question is very important for a Vishista-advaitin who believes that a Personal God exists in vyvaharika dormantly unless He she decides to intervene in the material world by for example awakening a gyan yogi as was the case with me. How can I be certain that a God awoke me. I might have just been an intrinsic part of Brahman awakening myself no matter the strength of evidence I have of visions of unfolding events in my life including prophetic utterrances and digital clock time checks as a means of exchanging messages with a hidden power within me.
Now having realised the mystery of the Self=Brahman and bgeing free of God in paramarthika, it seems possible that God creates Brahman and stays outside it to enter when needed and go away when He is no longer needed because the Self is self-sufficient in self-presrvation. However, some say that God is a creative aspect of Brahman. This would mean that Brahman being everything just 'is' always manifest, and is the ultimate Reality, not God.
The mind exists so long as one lives for ones body, the senses and its ego. In Self there is no mind and no universe to experience only Brahman exists.
Shantanu Panigrahi Yes I agree, ultimately. But surrender to a personal God can be a necessary avenue to realisation for some seekers. And any vision of their God that they might have due to intense devotion is as real as any perception of everyday life. In fact, it is MORE REAL. Swami Vivekananda, the great advocate of Advaita Vendanta, said of the Divine Mother, "She is real and thinks of herself as a Person." So we need to be aware of other apparent realities within the Absolute.
Brian Ritchie Thank you for reinforcing strongly my understanding of my personal experiences of going through 15 years of intense surrender to my own imagined (for good reason) personal God before I sought the distictive path that ends in Self realisation. I call myself a Vishista advaitin because of that VERY REAL bhakti devotion to Sri-Krishna-Durga is my yogic journey.
God is creative aspect of Brahman
Ramkrishna Kulkarni That Brahman has a creative aspect there seems little doubt. The universe that we experience is a creation of Brahman through what some call Maya. If this is accepted, then a Personal God is also one such creation of Brahman. It then follows that God did not create Brahman or the universe 8but both were created by Brahman which creates incessantly.