Deuteronomy 6:4 states, "Hear, O Israel: The LORD our God, the LORD is one." The New Testament affirms this, for example in Mark 12:29, Matthew 4:10, 1 Corinthians 8:4, and James 2:19. However, the Bible also says that both Jesus and the Holy Spirit are God. How can these seemingly contradictory statements be true?
Deuteronomy 6:4 says God is one; so how can Jesus be God?
In the Hebrew language, the word "one" found in Deuteronomy 6:4 is echad. This word refers to a "unity," not specifically a "singularity." This is the same word that refers to the husband and wife being "one flesh" in marriage (Genesis 2:24). This does not mean one single being, but living together in unity.
That being said, it is important to affirm the biblical teaching of one God. It is clear from the very beginning of the Bible that only one God created the heavens and the earth, and everything in it (Genesis 1:1—2:3). The question is not whether there is one God or many gods, but how Christians understand Jesus to be God. The Bible describes what Christians refer to as the Trinity or Triune God, consisting of Father, Son (Jesus), and Holy Spirit. These are not three separate gods who happen to be unified; neither is any of the members of the Trinity less than God. Rather, there is one God existing in three persons, as a unified whole. So, it is true that God is one, and it is true that Jesus is God.
We see Jesus' Godhood many times in Scripture. For example, in Matthew 1:18–25 we see that Mary, a virgin, will give birth to a son from the Holy Spirit. Joseph, who will be Mary's husband, is commanded to give this Son the name "Jesus" because He will save His people. Matthew adds that this is a fulfillment of Isaiah's prophecy that a virgin would conceive and bear a son and He would be called "Immanuel," which means "God with us." Jesus is God, in the flesh. He is God with us. He is also the one who saves us; only God can truly save.
At Jesus' baptism we see a clear image of the Trinity. Matthew 3:16–17 says, "And when Jesus was baptized, immediately he went up from the water, and behold, the heavens were opened to him, and he saw the Spirit of God descending like a dove and coming to rest on him; and behold, a voice from heaven said, 'This is my beloved Son, with whom I am well pleased.'" Here we see Father, Son, and Holy Spirit, each God and united as one.
During His life, Jesus walked in perfect unity with God, obeying His every command, preaching about the Good News, and paying the ultimate sacrifice on the cross to save us from our sins (Mark 1:1, 14; John 5:19–24; 10:30–38; 1 Corinthians 15:3–4). John 3:16 tells us, "For God so loved the world that he gave his only Son, that whoever believes in him should not perish but have eternal life." Jesus' death and resurrection were the ultimate sacrifice paid for our sins against an eternal God. For His sacrifice to be an adequate payment for our offenses against God, Jesus had to be God. Only an eternal God can pay an eternal penalty.
The Holy Spirit is also God. He is a Helper who remains in us forever (John 14:15–17) after we come to acknowledge who Jesus is, believe that He died and rose again, and confess that we are sinners and want to do God's will. Jesus promised to send the Holy Spirit when He left (John 16:7–15). All who belong to Jesus are sealed with the Holy Spirit (Ephesians 1:13–14).
After His resurrection, Jesus commanded His people to, "Go there 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). Here, again, we see the Trinity. Each of these three Persons that Jesus mentions are acting as one God. As Christians, we serve this Triune God.
First John 5:20 is clear that Jesus is God: "And we know that the Son of God has come and has given us understanding, so that we may know him who is true; and we are in him who is true, in his Son Jesus Christ. He is the true God and eternal life." Some struggle with the concept of God having a Son, or with seeing a "Son" as less than the Father. But the meaning of Jesus as the Son of God is not quite the same as a human father and son. Jesus is God in the flesh; "… in him all the fullness of God was pleased to dwell" (Colossians 1:19). God chose the Father/Son relationship to help us understand the relationships within the Trinity. The Father, Son, and Holy Spirit have existed as the Trinity—three Persons in a unified whole—from eternity past.
The Trinity is a challenging concept to understand, and in many ways it remains a mystery to us. The Bible is clear that God is one. The Bible is also clear that the Father, Jesus, and the Holy Spirit are God.
Is Jesus Christ God?
Did Jesus ever claim to be God? Is the deity of Christ biblical?
How is Jesus the Son of God?
What is the Trinity?
Is the Trinity really tritheism?
Truth about Jesus Christ