Robert W. Jenson from his book Systematic Theology: The Triune God, Volume I (New York and Oxford: Oxford University Press, 1997). His observations about "The Pneumatological Problem" can be found on pp. 146-161. I now present a brief summary of his statements.
Jenson, referencing Augustine, maintains that the Holy Spirit is
the "Gift of God." Manifestly, for Augustine, the Holy Spirit is God's Gift in that it is the bond of love eternally obtaining between the Father and the Son. Put more technically, the Spirit is the personal communion of the Father and the Son. In this case, Jenson contends, the genitive 'of' in "Gift of God" is "both subjective and objective: The Holy Spirit is God given by God" (page 147). But this description raises other questions. If the Spirit is God's Gift, then how is the Spirit "hypostatically" eternal? In other words, is the Spirit only a manifestation of divine identity in relation to Israel and the Church, or is the Spirit an immutable, necessary, and eternal personal distinction in the threefold Godhead? Furthermore, what hypostatic relation does the Spirit bear toward the Father and the Son?
Jenson's answers to these questions are quite interesting, even if
they are lacking in sufficiency. Read his book and you will see how
certain Trinitarian theologians try to resolve the seeming antinomies that result from the genitival "Spirit of God" etc. Foremost among such attempts to ameliorate the problemata resulting from the genitive use for the divine Spirit or "Gift of God" is the filioque approach contained in Western Trinitarian thought. But the Eastern Church rejects the filioque clause since it thinks the Spirit eternally proceeds solely from the Father (the one ARXH in the Godhead) and not the Son. I will thus conclude with this statement from Jenson:
"Perhaps the following is something like the truth. The
transcendental focus of the Spirit's intention of others is identical with the Father, for the Spirit's derivation of his being from the Father is never surpassed: the Spirit remains and is the spirit of someone; he is the RUACH of the God of Israel. And therefore as the Father finds his 'I' in the Son, so the Spirit finds his 'I' in the Son. He finds himself in the Son, however, differently than does the Father" (page 160).