He is the still point
One of the distinguishing characteristics of life is movement from within. The flower moves by growing, the butterfly moves through the air and man moves as a rational being. Creatures move by going from potency to act.
In the Summa we read the following objection, " It seems that life is not properly attributed to God. For things are said to live inasmuch as they move themselves, as previously stated. But movement does not belong to God. Neither therefore does life." St. Thomas Aquinas point out that God's act of understanding is his very nature and as such God is pure act or fully alive in whom there is no potency. (Part I, Q. 18, Art. 3) Likewise, the life between Father, Son and Spirit is not one of motion but of relationship of origin.
Another characteristic of life is reproduction. In God there there is only one eternal generation of the Son by the Father and spiration of the Spirit". The Father begot the Son in the Spirit from all eternity. "For just as the Father has life in himself, so also he gave to his Son the possession of life in himself." (Jn 5:26) Each Divine person does not share the life of God because in each person resides the fullness of God's life. Reproduction in creatures implies the creation of separate entities or separate persons as in the human dimension. In God the reality is different. The Persons or Relations between Father, Son and Spirit are distinct from one another but not separate. They form One entity, One God in such a way that the Father is God, the Son is God and the Spirit is God. In God there is fullness of existence and life.
God Creates Life