Kallistos Ware, in Reclaiming the Great Tradition, has stated that the Trinity is the “heart of our life.” I am posting more quotes by him from that book, showing how the Holy Spirit relates to the triune God:
God is a triunity of persons loving each other, and in that shared love the persons are totally “oned” without thereby losing their personal individuality. In the phrase of St. John of Damascus, . . . the Three are “united yet not confused, distinct yet not divided.” . . . The Father is the “fountainhead” within the Trinity, so that the Son and the Spirit find their unity in him and are defined by their relationship to him: the Son is begotten,” the Spirit “proceeds.” . . . In the case of the Trinity . . . every divine operation is one and undivided, and the Trinity has but one will and not three. In this manner the three persons of the Trinity are one in a way that three human persons can never be.