1. The Holy Spirit is the one that makes us children therefore we call out “Abba, Father!”
Romans 8:14–15 (NKJV) — 14 For as many as are led by the Spirit of God, these are sons of God. 15 For you did not receive the spirit of bondage again to fear, but you received the Spirit of adoption by whom we cry out, “Abba, Father.”
If we are the sons of God, if we have already begun to be his temples,65 if (after receiving the Holy Spirit) we live holily and spiritually, if we have lifted up our eyes from the earth toward heaven, if we have raised our hearts, full of God and Christ, to supernal and divine things, let us do nothing which is not worthy of God and Christ, as the apostle arouses and urges us.
St. Cyprian of Carthage, Jealousy and Envy

2. The Holy Spirit is the One who makes us the temple and dwells in us
1 Corinthians 3:16 (NKJV) — 16 Do you not know that you are the temple of God and that the Spirit of God dwells in you?
2 Corinthians 6:16 (NKJV) — 16 And what agreement has the temple of God with idols? For you are the temple of the living God. As God has said: “I will dwell in them And walk among them. I will be their God, And they shall be My people.”

3. The Holy Spirit is the one that gives the grace of Life through the Mysteries and Baptism
Romans 8:11 (NKJV) — 11 But if the Spirit of Him who raised Jesus from the dead dwells in you, He who raised Christ from the dead will also give life to your mortal bodies through His Spirit who dwells in you.
But he who raised Christ up from the dead will raise us up also if we do his will and walk in his commandments and love what he loved, keeping ourselves from all unrighteousness, covetousness, love of money, evil-speaking, false witness, “not rendering evil for evil, or railing for railing,”22 or blow for blow, or cursing for cursing, but being mindful of what the Lord said in his teaching.
St. Polycarp, The Epistle to the Philippians 2.

4. The power of the Holy Spirit is the One working in us through word, deed, signs, and wonders
Romans 15:18–19 (NKJV) — 18 For I will not dare to speak of any of those things which Christ has not accomplished through me, in word and deed, to make the Gentiles obedient—19 in mighty signs and wonders, by the power of the Spirit of God, so that from Jerusalem and round about to Illyricum I have fully preached the gospel of Christ.

5. The power of the Holy Spirit makes us free from all weakness and sin
2 Corinthians 3:17 (NKJV) — 17 Now the Lord is the Spirit; and where the Spirit of the Lord is, there is liberty.
Just like children, so are the Jews also under a tutor. The law is our tutor; a tutor brings us to the master; Christ is our only master.… A tutor is feared, the master points out the way to salvation. Fear brings us to liberty, liberty to faith, faith to love, love obtains adoption, adoption an inheritance. Therefore, where there is faith, there is freedom, for a slave acts in fear, a free man through faith. The one is under the letter, the other under grace; the one in slavery, the other in the spirit; for “Where the Spirit of the Lord is, there is freedom.”.
St. Ambrose of Milan, Letter 69.

6. Through the work of the Holy Spirit Christ is formed in us
Through the work of the Holy Spirit Christ is formed in us. The Holy Spirit recreates us, builds us up in the future to the point that we are like Christ and spiritual beings
Galatians 4:19 (NKJV) — 19 My little children, for whom I labor in birth again until Christ is formed in you,
Christ is “formed in you” by nothing else but irreproachable faith and the way of gospel. St. Cyril of Alexandria, Festal Letter 10.1

7. The work of the Holy Spirit is in the choosing of the Bishops and gives them knowledge and understanding
Jeremiah 3:15 (NKJV) — 15 And I will give you shepherds according to My heart, who will feed you with knowledge and understanding.

8. Acts 20:28 (NKJV) — 28 Therefore take heed to yourselves and to all the flock, among which the Holy Spirit has made you overseers, to shepherd the church of God which He purchased with His own blood.
Since it is not according to nature but according to an appropriation of the power that comes from the Spirit that a person is ordained to the episcopacy by the Holy Spirit for our sake, it is possible for one holding such a position to fall from it, without due care. For if someone were established as a shepherd of the church because of the state of his being, that person would hold whatever office without possibility of change. But it not only says that bishops must pay heed to themselves but also to the flock that the Savior acquired by his blood. St. Didymus the Blind, Catena on the Acts of the Apostles 20.28

9. The Holy Spirit is the one Whom we dwell in and the One whom we live, move, and have our being
John 6:63 (NKJV) — 63 It is the Spirit who gives life; the flesh profits nothing. The words that I speak to you are spirit, and they are life.

10. Acts 17:28 (NKJV) — 28 for in Him we live and move and have our being, as also some of your own poets have said, ‘For we are also His offspring.’
Learn now that as the Father is the Fount of life, so, too, many have stated that the Son is signified as the Fount of life.11 This is why he says that with you, almighty God, your Son is the Fount of life. That is the Fount of the Holy Spirit, for the Spirit is life, as the Lord says: “The words that I have spoken to you are spirit and life,” for where the Spirit is, there also is life. And where life is, there is also the Holy Spirit.
St. Ambrose of Milan, On the Holy Spirit

11. It is clear that the Father and the Son dwell in the saints through the Holy Spirit
The Holy Spirit is the one who fulfills the presence of the Father and the Son in you
John 14:23 (NKJV) — 23 Jesus answered and said to him, “If anyone loves Me, he will keep My word; and My Father will love him, and We will come to him and make Our home with him.

12. The Holy Spirit divides the Grace of God amongst the people as He wills
1 Corinthians 12:8–11 (NKJV) — 8 for to one is given the word of wisdom through the Spirit, to another the word of knowledge through the same Spirit, 9 to another faith by the same Spirit, to another gifts of healings by the same Spirit, 10 to another the working of miracles, to another prophecy, to another discerning of spirits, to another different kinds of tongues, to another the interpretation of tongues. 11 But one and the same Spirit works all these things, distributing to each one individually as He wills.

13. Christ dwells in us through the Holy Spirit and the Holy Spirit reforms you into the image of the Son
Ephesians 3:16–17 (NKJV) — 16 that He would grant you, according to the riches of His glory, to be strengthened with might through His Spirit in the inner man, 17 that Christ may dwell in your hearts through faith; that you, being rooted and grounded in love,

14. The love of God is poured out by the Holy Spirit who dwells in you
Romans 5:5 (NKJV) — 5 Now hope does not disappoint, because the love of God has been poured out in our hearts by the Holy Spirit who was given to us.

15. The Holy Spirit gives you knowledge, understanding, spiritual wisdom, and authority to do miracles, wonders, and signs.
“Having sent the Holy Spirit upon the apostles on the day of Pentecost, He came upon each one of them like divided tongues of fire, and filled them with all knowledge, all understanding, and all spiritual wisdom, according to Your faithful promise…O You who granted His holy disciples and honored apostles the descent of the Spirit, the Paraclete, upon them and gave them authority to work healings, signs, and wonders…” (Fraction of the Apostles)
Isaiah 11:2 (NKJV) — 2 The Spirit of the Lord shall rest upon Him, The Spirit of wisdom and understanding, The Spirit of counsel and might, The Spirit of knowledge and of the fear of the Lord.