To say the personal God is not fully real is not to say He is unreal. You seem to be thinking of a strict black-or-white dichotomy: either real or not, either completely true or completely false.

The key here is to remember the idea of a “great chain of being”, with degrees of reality ranging from the supreme Principle to nothingness. Remember what Schuon said in the chapter on Ved?nta our class recently read from Spiritual Perspectives and Human Facts: “It is not possible to understand that the enunciation ‘Brahma is the Almighty Creator’ contains an error before having understood that it expresses a truth.”

God as Being may be less real than God as Beyond-Being, but God as Being is nonetheless infinitely more real than His creatures, ourselves included. The mistake I think you’re making is this: you think you’re being asked to suppose that we mere mortal creatures, indeed fallen egos, are somehow the creators of the personal God, who is thus merely a figment of our imaginations. Not so, and indeed just the opposite. The metaphysician would prefer to say—though this is somewhat ill sounding, I realize—that we are merely figments of God’s imagination.

No matter how “fully realized” a given sage might be, he remains—and he knows it!—a creature of the Divine Creator. The key chapter of Schuon’s on this subject is “The Servant and Union”, in Logic and Transcendence.