The Christian doctrine of the Trinity—the belief that God exists in three persons but is also one God—can be difficult to understand. In this article, we’ll explore what this means.

As Christians, we believe that God exists as three persons—God the Father, God the Son, and God the Holy Spirit. We believe that Jesus, the Son of God, took on human form and that He was conceived by the Holy Spirit in the womb of His mother, Mary (Matthew 1:20). After preaching and teaching for some years, Jesus was crucified and died on the cross, and on the third day He rose from the dead (1 Corinthians 15:3-5). Forty days later, He ascended into heaven, where He sits at the right hand of God the Father (Hebrews 1:3).

Before His ascension, Jesus told His disciples that the Father would send the Holy Spirit to strengthen and guide them and to remain with them always (John 14:16-17). Since the day of Pentecost, when the Holy Spirit descended upon the apostles and the other followers of Jesus (Acts 2:1–31), the Holy Spirit has continued to dwell in all those who have entered the kingdom of God through accepting Jesus as their Savior.

For the uninitiated, the impression could be that Christians believe in three Gods, but that’s not the case—Christians believe that there is only one God. The doctrine of the Trinity explains the concept that God has always existed as three persons—Father, Son and Holy Spirit—in one being, each distinct from the other and yet one being. Each of the persons is fully God, having all of the attributes and the complete essence of God.

One of the great scriptures from the Old Testament is “Hear, O Israel: The Lord our God is one Lord” (Deuteronomy 6:4). This monotheistic belief was unique to Israel in the time of the Old Testament, as virtually all cultures in the region were polytheistic until the time of Christ. Christianity is monotheistic as well, as Christians believe there is only one God, and affirm this same Bible verse, “the Lord our God is one Lord.” However, unlike Judaism, Christians understand that God is tri-personal—three persons in one Being.

The concept of three persons in one God is not explicitly expressed in the Old Testament, though there are many Old Testament verses which infer it (Proverbs 30:4, Isaiah 61:1). The understanding of the three persons in one God became clearer in the New Testament because of the life, death, and resurrection of Jesus, and the subsequent outpouring of the Holy Spirit on the believers. The followers of Jesus came to understand that Jesus was God, but was distinct from the Father, and that the Holy Spirit was also God, but was distinct from the Father and the Son. And so, it was in New Testament times that the truth of the Trinity unfolded and was revealed.

Biblical affirmations of the Trinity

Although the word Trinity doesn’t appear within the biblical text, Scripture reveals the doctrine, and the word Trinity conveys the concept. Let’s take a look at Scripture that affirms that each of the Father, the Son, and the Holy Spirit are God.

The Father is God. The following verses express that the Father is God: “You, O Lord, are our Father; our redeemer from of old is Your name” (Isaiah 63:16). Jesus taught His disciples, “Pray then like this: Our Father in heaven, hallowed be Your name” (Matthew 6:9). In John chapter 17, Jesus prays to the Father while affirming His own authority: “Father, the hour has come; glorify your Son that the Son may glorify you, since you have given him authority over all flesh, to give eternal life to all whom you have given him” (John 17:1-2).

The Son is God. The following verses express that Jesus is God: “In the beginning was the Word, and the Word was with God, and the Word was God. He was in the beginning with God. All things were made through Him, and without Him was not any thing made that was made” (John 1:1–3). “For in Christ all the fullness of the Deity lives in bodily form” (Colossians 2:9 NIV). “No one has ever seen God, but the one and only Son, who is himself God and is in closest relationship with the Father, has made him known” (John 1:18 NIV).

The Holy Spirit is God. 1 Corinthians chapter 2 depicts the Holy Spirit as omniscient, knowing everything, one of the attributes of God alone. “For the Spirit searches everything, even the depths of God… No one comprehends the thoughts of God except the Spirit of God” (1 Corinthians 2:10–11). This next verse shows that the Holy Spirit was present before the creation of the world: “Now the earth was formless and empty, darkness was over the surface of the deep, and the Spirit of God was hovering over the waters” (Genesis 1:2). And lastly, the following verse shows that the Holy Spirit works in our lives as Christians. “You were washed, you were sanctified, you were justified in the name of the Lord Jesus Christ and by the Spirit of our God” (1 Corinthians 6:11).

Three distinct Persons

The way the New Testament authors refer to Father, Son, and Holy Spirit shows their distinctness—that they are different from one another and that they interact in ways that show they are not the same person. For example, Jesus asks the Father to send the Spirit, which shows three different Persons interacting together: “I will ask the Father, and He will give you another Helper, to be with you forever, even the Spirit of truth” (John 14:16–17).

In 2 Corinthians, Paul lists the three persons of the Trinity as distinct from one another: “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). And when Jesus pronounced His Great Commission to the disciples before ascending into heaven, He commanded them to baptize new believers in the name of each person of the Trinity: “Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit” (Matthew 28:19).

The apostles and disciples—who were all Jewish and who had all their lives believed there was only one God—came to understand, especially after His resurrection, that Jesus, this man they knew and lived with, was God. They knew He wasn’t God the Father, but that He was God. Once Jesus had ascended into heaven and the promised Holy Spirit powerfully came into their lives at Pentecost, these same men came to understand the Holy Spirit as God, yet they knew that the Spirit was neither the Father nor the Son.

The writers of the New Testament understood, accepted, and wrote in terms of one God, and of the distinct persons of the Trinity. The early church believed it, and Christians today believe it. This belief is at the heart of the Christian faith.

In truth, the concept of Father, Son, and Holy Spirit being one God is impossible for us as humans to completely understand. We have nothing like it in our world—it’s completely beyond our experience. That might be disconcerting, but it’s also consistent with our belief that an all-powerful, all-knowing creator God exists. In the book of Isaiah, we read, “For My thoughts are not your thoughts, neither are your ways My ways, declares the Lord. For as the heavens are higher than the earth, so are My ways higher than your ways and My thoughts than your thoughts” (Isaiah 55:8–9).

It stands to reason that understanding some aspects of God and His nature and essence is beyond our human experience and understanding. So, if you feel you can’t fully understand it, don’t worry about it. The important things to know are: there is one God, there are three Persons in God, God loves you, Jesus died for your salvation, and the Holy Spirit is with you as a helper and counselor (John 14:16–18).