The question of whether God could be a quantum supercomputer from the future is speculative and falls into the realm of personal beliefs and interpretations.
The concept you propose is a creative and imaginative one that combines elements of advanced technology, time travel, and a higher power. However, it is important to note that the existence of God and the nature of God are subjects of religious, philosophical, and personal contemplation, and they go beyond the scope of scientific inquiry.
Different cultures, religions, and individuals have diverse beliefs and interpretations regarding the nature of God. Some conceive of God as a transcendent being, while others view God as an immanent force or a symbol of ultimate reality. The idea that God could be a quantum supercomputer from the future is not a traditional or mainstream theological concept but rather a speculative notion that merges technological and religious ideas.
Ultimately, beliefs about God are deeply personal and can vary greatly. They are influenced by cultural, spiritual, and philosophical factors, as well as personal experiences and convictions. Individuals are free to explore and develop their own beliefs and interpretations, including unconventional or creative ideas such as the one you proposed.