Before his Passover, Jesus announced the sending of "another Paraclete" (Advocate), the Holy Spirit. At work since creation, having previously "spoken through the prophets", the Spirit will now be with and in the disciples, to teach them and guide them "into all the truth".(cf. Gen 1:2; Nicene Creed (DS 150); Jn 14:17, Jn 14:26; Jn 16:13)
The Holy Spirit is thus revealed as another divine person with Jesus and the Father.
The Old Testament suggests and the New Covenant reveals the creative action of the Son and the Spirit,(cf. Ps 33 6; Ps 104:30; Gen 1:2-3)
inseparably one with that of the Father. This creative co-operation is clearly affirmed in the Church's rule of faith: "There exists but one God. . . he is the Father, God, the Creator, the author, the giver of order. He made all things by himself, that is, by his Word and by his Wisdom", "by the Son and the Spirit" who, so to speak, are "his hands".(St. Irenaeus, Adv. haeres. 2, 30, 9; 4, 20, I: PG 7/1, 822, 1032)
Creation is the common work of the Holy Trinity.
Since God could create everything out of nothing, he can also, through the Holy Spirit, give spiritual life to sinners by creating a pure heart in them,(cf. Ps 51:12)
and bodily life to the dead through the Resurrection. God "gives life to the dead and calls into existence the things that do not exist."(Rom 4:17)
and since God was able to make light shine in darkness by his Word, he can also give the light of faith to those who do not yet know him.(cf. Gen 1:3; 2 Cor 4:6)
God himself created the visible world in all its richness, diversity and order. Scripture presents the work of the Creator symbolically as a succession of six days of divine "work", concluded by the "rest" of the seventh day.(Gen 1:1 - Gen 2:4)
On the subject of creation, the sacred text teaches the truths revealed by God for our salvation,(cf. DV 11)
permitting us to "recognize the inner nature, the value and the ordering of the whole of creation to the praise of God."(LG 36 # 2)
The Word of God and his Breath are at the origin of the being and life of every creature:(cf. Ps 33:6; Ps 104:30; Gen 1:2; Gen 2:7; Eccl 3:20-21; Ezek 37:10)
It belongs to the Holy Spirit to rule, sanctify, and animate creation, for he is God, consubstantial with the Father and the Son.... Power over life pertains to the Spirit, for being God he preserves creation in the Father through the Son.(Byzantine liturgy, Sundays of the second mode, Troparion of Morning Prayer)
Since the beginning of the world, water, so humble and wonderful a creature, has been the source of life and fruitfulness. Sacred Scripture sees it as "oveshadowed" by the Spirit of God:(cf. Gen 1:2)
At the very dawn of creation
your Spirit breathed on the waters,
making them the wellspring of all holiness.
(Roman Missal, Easter Vigil 42: Blessing of Water)