yes ... but but but
there is One God, but he is Three in One, a bit like the Hindu Trinity except not
however presumably the essence of each of the three is spirit, it can't be matter - the Son may have been clothed in matter for a while but it's a temporary thing like putting on a hat
some fringe Christians do definitely speak in terms of human spirit (soul) being a piece or aspect of the One God
so for Christians, and I stand to be corrected on this but I presume Jews and Muslims as well, the fundamental division is really dualist - spirit and matter