The Spirit resides in our heart. It's the reflection of God Almighty. In Sanskrit language: this aspect of God which is all-pervading and is the first and the last, is called as Sadashiva, is the Father, who does not incarnate. We say Yehova, you can say, or the God who does not incarnate. This great aspect which encompasses everything ultimately and also manifests everything, is reflected within our heart as the Spirit. This aspect is just the witness aspect. It witnesses the play of its power, the Primordial Power, the Holy Ghost, to see what is created by Her. He's the only enjoyer of the game. He sees the game, the leela, the fun. She organizes everything, it is She who gets divided into three powers, it is She who creates the whole universe, it is She who gives us this evolution, it is She who makes us human beings and it is She who has to make us the higher human being. That's the Holy Ghost, the Primordial Holy Ghost and the reflection of that is this Kundalini within us.
Shri Mataji Nirmala Devi October 7, 1981 " Spirit - Satchitananda " Public Program Houston, Texas USA