Introduction

"God is love." (1 John 4:8, 16)

"The grace of the Lord Jesus Christ and the love of God and the fellowship of the Holy Spirit be with you all." (2 Corinthians 13:14)

The love of God: The overflowing love of the Father.
The grace of the Lord Jesus Christ: The sacrificial love of the Son.
The fellowship of the Holy Spirit: The welcoming love of the Spirit.

"But when the fullness of time had come, God sent forth his Son, born of woman, born under the law, to redeem those who were under the law, so that we might receive adoption as sons. And because you are sons, God has sent the Spirit of his Son into our hearts, crying, 'Abba! Father!'” (Galatians 4:4–6, ESV)

God —> Son —> Adoption —> God —> Spirit —> Us —> God

What God is This?

A Trinity

God (Father) sent forth his Son
Son was born of woman and under the law
The Spirit comes to dwell within us

Scripture

God is One
- The Shema (hear, listen): “Hear, O Israel: The Lord our God, the Lord is one. You shall love the Lord your God with all your heart and with all your soul and with all your might.” (Deut. 6:4-5)
- Backing up Shema
  - “Jesus answered, “The most important is, ‘Hear, O Israel: The Lord our God, the Lord is one.” (Mark 12:29, ESV)
  - “...God is one.” (Galatians 3:20, ESV)
  - “You believe that God is one; you do well. Even the demons believe—and shudder!” (James 2:19, ESV)
- All of Scripture
  - “You shall have no other gods before me.” (Exodus 20:3, ESV)
  - “...the Lord is God; there is no other besides him.” (Deuteronomy 4:35, 1 Kings 8:60)
  - “...besides me there is no god.’” (Isaiah 44:6, 45:5, ESV)
  - “I am the Lord, and there is no other.” (Isaiah 45:5, 6, 18 ESV)
  - “And this is eternal life, that they know you, the only true God, and Jesus Christ whom you have sent.” (John 17:3, ESV)
  - “...one God...” (Ephesians 4:4–6, ESV)
  - “For there is one God...” (1 Timothy 2:5, ESV)
- The Father is God
  - The Father is identified as the only true God in Jesus’ high priestly prayer: “And this is eternal life, that they know you, the only true God, and Jesus Christ whom you have sent” (John 17:3).
  - Paul further emphasizes the Father’s central role in creation and salvation, writing, “Yet for us there is one God, the Father, from whom are all things and for whom we exist” (1 Corinthians 8:6).
- The Son is God
  - John’s Gospel opens with a clear declaration of his deity: “In the beginning was the Word, and the Word was with God, and the Word was God” (John 1:1). He is the eternal Word, who “became flesh and dwelt among us” (John 1:14).
  - Just by calling God his Father, Jesus was claiming to be equal with God, and one cannot be equal with God without being God (John 5:18). Jesus himself claimed divine authority, saying, “I and the Father are one” (John 10:30), and accepted worship, as seen in Thomas’ exclamation, “My Lord and my God!” (John 20:28).
  - Jesus equated himself with the great I AM, Yahweh’s name, in John 8:58.
  - Paul affirms this truth in Colossians 2:9, stating, “For in him the whole fullness of deity dwells bodily,” underscoring that Jesus is not merely like God but is fully God.
  - Hebrews declares him as the radiance of God’s glory, the exact imprint of God’s nature, and the one who upholds the universe by the word of his power (Heb. 1:3).
  - His divine authority extends to forgiving sins, a prerogative reserved for God alone, as evidenced in his words, “But that you may know that the Son of Man has authority on earth to forgive sins” (Mark 2:10).
  - Paul identifies Jesus as the Creator and Sustainer of all things: “For by him all things were created, in heaven and on earth, visible and invisible…and in him all things hold together” (Col. 1:16–17).
  - In Philippians, Paul tells us that Jesus, the very form of God, equal with God, humbled himself, emptied himself, was found in human form, and died on the cross for us (Philippians 2:6-11).
  - In Revelation, Jesus is described as the Alpha and Omega, titles reserved for God, declaring, “I am the Alpha and the Omega, the first and the last, the beginning and the end” (Rev. 22:13).
- The Spirit is God
  - Though there is less mention of the divinity of the Spirit in Scripture, the argument is still forceful and clear. Additionally, a major role of the Spirit is to promote the Son (John 15:26, 16:13-14, 1 Cor. 12:3, 1 John 4:2), so it stands to reason that the book the Spirit helped pen (2 Pet. 1:21) would not draw as much attention to his being.
  - That said, here are a few passages pointing to the truth of the Spirit’s divinity: The Holy Spirit is eternal and omnipresent, as seen in Hebrews 9:14, where he is called the “eternal Spirit,” and Psalm 139:7-10, which declares that no one can flee from his presence.
  - His omniscience is demonstrated in 1 Corinthians 2:10-11, where he comprehends the depths of God.
  - He is omnipotent, as evidenced in Genesis 1:2, where he participates in creation, and Job 33:4, which credits him with giving life.
  - The Spirit is explicitly referred to as God in Acts 5:3-4, where lying to the Holy Spirit is equated with lying to God, and in 2 Corinthians 3:17-18, which states, “the Lord is the Spirit.”
  - His divine authority is evident in his role in inspiring Scripture (2 Timothy 3:16, 2 Peter 1:21), empowering believers (Acts 1:8), and distributing spiritual gifts as he wills (1 Corinthians 12:4-11).
  - The Spirit sanctifies believers (1 Peter 1:2), intercedes for them in prayer (Romans 8:26-27), and works in the process of regeneration and renewal (John 3:5-6, Titus 3:5).
  - His divine nature is further revealed in the Trinitarian formula used in Matthew 28:19 and 2 Corinthians 13:14, where the Spirit is included alongside the Father and the Son as fully God.
  - Thus, Scripture presents the Holy Spirit as a distinct person who shares the essence, attributes, and authority of the one true God. These passages, and others like them, firmly declare the Spirit as God.

Implications of the Doctrine of the Trinity

Illustration: How to describe sunlight streaming through a window on a cold winter's day:
- Perhaps you would elaborate on the way it penetrates the gray of the season and lifts your mood. You could describe the warmth of its touch on your pale skin. You may revel in its color and beauty. Perhaps you would soak in its life-giving properties. You might even pause your day to sit in its presence, warmed by its gentle touch.
- Scientifically, that same light could be explained in far different ways. You might detail that it is electromagnetic radiation, traveling at astonishing speeds, consisting of wavelengths we perceive as visible light. You could analyze its intensity, angle, and source. You could explain how its ultraviolet rays affect human skin and promote vitamin D production.
- While both approaches to describing the sunlight in that room, one focuses on the scientific analysis, while the other focuses on the light’s impact on human life and experience.
- God’s Triune can be described systematically—God is one essence in three persons: Father, Son, and Holy Spirit, each fully God, co-equal and co-eternal. This explanation is true and necessary, but it is only the beginning. The Trinity is not a cold abstraction to be filed away in theological textbooks; it is the very heart of God’s revelation to us and the foundation of our relationship with him.
The Trinity gives us a relational God. The Father loves the Son eternally through the Spirit (John 17:24), offering believers a God who is not distant but deeply involved. Unlike solitary gods of other worldviews, the Triune God invites humanity into divine fellowship. He is not self-absorbed and aloof, existing in solitary grandeur, but interested in a relationship with his creation because, by his nature, he is relational.
The Trinity gives us salvation. Without it, the cross loses its coherence, and our salvation falls apart. Without the Trinity, the cross becomes merely a tragic event, not a glorious display of self-giving love. The Father, Son, and Spirit join together in working for our salvation. The Father initiates, the Son accomplishes, and the Spirit applies redemption (Eph. 1:3-14). This cooperative work assures believers of God’s complete commitment to their rescue.
The Trinity gives us a God of love. Only a Triune God whose eternal essence is that of love, who has practiced love for eternity past within himself, can demonstrate love, grace, and mercy as intrinsic parts of his being. Love flows naturally from God’s nature, making grace and mercy the foundation of creation and redemption (1 John 4:7-10).
The Trinity gives us a model for relationships. By reflecting on the love, mutuality, unity, fellowship, and outward focus within the Godhead (Gen. 1:26-27), we can find guidance and inspiration for cultivating healthy, fulfilling relationships that mirror the beauty and harmony of the Trinity. The Father and Son’s relationship gives our marriages a model (Gen. 2:18, Eph. 5:21-33), while the fellowship of the entire Trinity speaks to us of the importance of sharing life with others. God did not make us a solitary species (Gen. 2:18). We are relational because the God who made us is relational (1 John 4:7-12).
The Trinity gives us transformational power. Because God is Triune, we can receive God’s aid in our transformation process. As we meditate upon the Son, the Spirit remakes us into his image (2 Cor. 3:18). As we walk in the Spirit, we are empowered to love God and live as the Son, delighting in obedience to the Father’s will (Rom. 8:14-17, Gal. 4:6-7, 5:22-25). Our obedience can, by the Spirit’s aid, become a joy rather than a mere duty (Phil. 2:1-2).
The Trinity gives us a basis for joy and fellowship. The Father’s delight in the Son becomes ours as the Spirit brings us into divine communion (Matt. 3:16-17, John 15:9-11). This joy leads to unity in the church and harmony with other believers (John 17:22-26). The Father's love for the Son isn't simply an emotion but an essential, defining aspect of his being. This love is so abundant that he desires to share it with others, forming the very heart of the gospel message. Believers are united with Christ through the Holy Spirit, becoming God's adopted children and sharing in the Father's love for the Son, leading to great joy before God and fellowship with others.
The Trinity gives us a basis for beauty and harmony. First, the Trinity is beautiful (Ps. 27:4). This beauty stems from the perfect love and unity shared between the Father, Son, and Spirit (John 17:21-23). This Triune God is the ultimate source and standard for beauty. Second, the creation the Trinity produced is also beautiful (Gen. 1:1-3, Col. 1:16-17). God made a world where different elements complement and work together (Ps. 19:1, Is. 6:3). Varying musical notes, colors, and elements in the natural world demonstrate the Trinity’s harmony, beauty, and order (Ps 104:24-25, Rev. 4:11).
The Trinity gives us hope in a broken world. God is one in essence but three in persons, which provides us a framework for his actions in human history (Is. 46:9-10, John 6:39-40). The Father’s plan, the Son’s incarnation, and the Spirit’s ongoing renewal assure humanity of a loving God at work to redeem and restore are our great hope (Rom. 8:18-23).
The Trinity gives us unity in diversity. The Trinity models unity without erasing diversity (Eph. 2:14-16). This inspires the church to embrace cultural, ethnic, and personal differences while remaining one body in Christ (Eph. 4:4-6), pointing to the ultimate reconciliation of all things (Eph. 1:9-10). Anecdotal evidence suggests that strict monotheism struggles to produce variety or diversity in expressions of worship or cultural styles, while Christianity has found ways to thrive among every nation, tribe, and tongue.
The Trinity gives us a self-sufficient God who overflowed in love for us. The Trinity sets the Christian God apart from all other conceptions of deity. A solitary god might demand worship out of need, but the Triune God is self-sufficient, overflowing with love that spills into creation and redemption (John 17:24, Acts 17:24-25). Unlike impersonal or distant gods, the Trinity demonstrates God’s relational, self-giving nature, inviting humanity into divine joy and fellowship (Rom. 5:8, Eph. 1:3-6). This relational love makes sense of the gospel, explaining why the Son would die and why the Spirit dwells in believers (John 14:16-17).
The Trinity gives us a mission. Because the Father’s love for the Son overflows into the creation, love is the driving force for the Father to send the Son to redeem creation (Matt. 28:18-20, John 3:16). The “missional, generous, outgoing shape of God’s own life” helps shape us and sends us out into a world in need of redemption. Our mission is to share the gospel, but the goal of the gospel, in a sense, is to expand the Trinitarian fellowship (John 17:21-23, Rev. 7:9-10). Our mission is to help people know and be in a relationship with God, and God aids us in that mission (Acts 1:8).

What Love is This?

God —> Son —> Adoption —> God —> Spirit —> Us —> God
"There is a river whose streams make glad the city of God, the holy habitation of the Most High." (Psalm 46:4, ESV)
"...for my people have committed two evils: they have forsaken me, the fountain of living waters, and hewed out cisterns for themselves, broken cisterns that can hold no water." (Jeremiah 2:13, ESV)
"...but whoever drinks of the water that I will give him will never be thirsty again. The water that I will give him will become in him a spring of water welling up to eternal life.” (John 4:14, ESV)
Fullness of time
- Historically
  - Pax Romana—peace, roads, language
  - Christmas story
- Biblically
  - Ps. 22—crucifixion
  - Dan. 9—483 years after rebuilding Jerusalem
  - Gen. 3:15—snake crusher
  - Gen. 12:1-3—who would bless all nations
- Personally
  - Your life!

Conclusion

I know the God for whom your soul thirsts.
From God, to us, back to God, to others!
- Mark 5—demoniac

Study Questions:

Head (Knowledge, Facts, Understanding):

What does Galatians 4:4-6 reveal about the roles of the Father, Son, and Holy Spirit in God’s redemptive plan?
How does Scripture affirm the doctrine of the Trinity, and what specific passages highlight the divinity of the Father, Son, and Spirit?
In what ways does the concept of the Trinity help explain the nature of God’s love as relational and self-sufficient?

Heart (Feelings, Impressions, Desires):

How does understanding God as a Trinity deepen your appreciation of His love for you?
Reflect on the image of God’s love “overflowing” to you—how does this impact your sense of identity and belonging?
What emotions arise when you consider the Father’s love for the Son being extended to you through adoption and the Spirit’s indwelling?

Hands (Actions, Commitments, Decisions):

How can the relational unity of the Trinity serve as a model for improving your relationships with others?
In what practical ways can you reflect the self-giving love of the Trinity in your daily life this week?
Considering the mission of the Trinity to redeem and restore, how can you contribute to sharing God’s love in your community?