You know you exist because you think, perceive, plan, formulate logic, abstract reasoning etc which are not the characteristics of matter. Science does not discover the self; but it is the self that discovers science. You are an individual, and the word individual is from indivisible, Latin [in + dividuus “divisible”, from divido “divide”. Individual is all about your immaterial substratum on which body is sustained. This substratum is indivisible, minuter than the minutest, not composed of parts, cannot be destroyed. This applies to God who is also an individual made of qualities like we are. The only difference: among many individuals one would be Supreme because humans cannot say ‘no one superior to us exists.’ Supreme Soul would have supreme qualities, and would have a residence that matches His Supreme status.
God is individual, simple in composition, atom-sized, hence anthropomorphic representation of God is untruth. This is where all religions went wrong. Things such as imagery, symbols .. inadequate to explain the Supreme.