St. Nicholai Velimirovich
The Father has perfect love for the Son and the Spirit. The Son has perfect love for the Father and the Spirit. And the Spirit has perfect love for the Father and the Son. According to this perfect love, the Father is in the most zealous obedience to the Son and the Spirit, and the Son is in the most zealous obedience to the Father and the Spirit; and the Spirit is in the most zealous obedience to the Father and the Son. Perfect love makes the Father the perfect servant of the Son and the Spirit; and the Son, the perfect servant of the Father and the Spirit; and the Spirit, the perfect servant of the Father and the Son. Just as no love in the created world can be compared to the mutual love of the Divine Hypostasis, neither also can any obedience be compared to Their mutual obedience. I have glorified Thee on earth: I have finished the work which Thou gavest me to do (Jn. 17:4). May Thy will be done. Are these not the words of the Son’s perfect obedience to the Father? Father, I thank Thee that Thou hast heard me. And I knew that Thou hearest me always, said the Lord Jesus Christ at the resurrection of Lazarus; and later He would exclaim: Father, glorify Thy name. Then came there a voice from heaven, saying, I have both glorified it, and will glorify it again (Jn. 11:41–42; 12:28). Is this not the perfect obedience of the Father to the Son? Nevertheless I tell you the truth; It is expedient for you that I go away: for if I go not away, the Comforter will not come unto you; but if I depart, I will send him unto you (Jn. 16:7). And I will pray the Father, and he shall give you another Comforter, that he may abide with you forever… But when the Comforter is come, whom I will send unto you from the Father, even the Spirit of truth, which proceedeth from the Father, he shall testify of me (Jn. 14:16; 15:26). And truly, on the fiftieth day after the Resurrection, the Comforter, Spirit of Truth descended upon those to whom it was promised. Is this not the perfect obedience of the Holy Spirit to the Son?
And the salvific rule that the Apostle Paul commands all the faithful to keep: Be kindly affectioned one to another with brotherly love; in honour preferring one another (Rm. 12:10)—is perfectly performed between the Hypostases of the Holy Trinity. Each one of the Hypostases strives to prefer one another in honor; so also does each wish to decrease Himself before the Other Two. And if each Hypostasis did not have that most sweet and holy striving to render His honor to the Other Two and decrease Himself in obedience, then in that endless love, which Each of them has for Each Other, the Trinitarian nature of the Divinity would drown in a kind of indifference of Hypostasis.
From the collected works of St. Nicholai (Velimirovich)
St Symeon the New Theologian wrote this invocation to the Holy Spirit:
Come, O true light!
Come, O eternal life!
Come, O hidden mystery!
Come, O indescribable treasure!
Come, O ineffable thing!
Come, O inconceivable person!
Come, O endless delight!
Come, O unsetting light!
Come, O true and fervent expectation of all those who will be saved!
Come, O rising of those who lie down!
Come, O resurrection of the dead!
Come, O powerful one, who always creates and re-creates and transforms by your will alone!…