If the Holy Spirit is the third Person of a Trinity, then is not the spirit in man also another man? — Herbert W. Armstrong (Mystery of the Ages, New York: Dodd, Mead & Company, 1985, page 112.)
The time-honored belief in a divine Trinity posits the idea that the Holy Spirit is the third Person in that Trinity, in addition to the Father and the Son. The Spirit, according to this belief, is not just the power of God but also a distinct Person, as are the Father and the Son.