The Bible teaches that God is one God in three distinct persons: God the Father, God the Son, and God the Holy Spirit. This teaching is commonly known as the Trinity – meaning that God is a “tri-unity” or “three-in-one.” Now let me make it clear that Christians do not believe in three Gods. Nor does the Bible teach that God is one person who appears in three different forms or modes, which is an error sometimes known as modalism or Oneness Pentecostalism. Though the concept that God is one God in three distinct persons may be difficult for us to grasp, it is what Scripture clearly teaches.
One God, Three Persons
First, the Bible teaches that God is one:
Hear, O Israel: The LORD our God is one LORD (Deuteronomy 6:4)
For I am God, and there is no other. (Isaiah 45:22)
The Bible clearly teaches that there are not three Gods, but one true God. However, Scripture also teaches that there are a plurality of persons in the Godhead.
God the Father is:
God – Phil 1:2
Creator – Gen 1:1
Eternal – Psalm 90:2
God the Son is:
God – John 1:1; Romans 9:5; Col 2:9; Tit 2:13; Heb. 1:5-13
Creator – Col 1:16
Eternal – John 8:58; (cf. Ex 3:14)
God the Holy Spirit is:
God – Acts 5:3-4
Creator – Job 33:4; Job 26:13
Eternal – Heb 9:14
This teaching that all three persons in the triune Godhead are One God but three distinct persons, is seen throughout Scripture:
In the beginning was the Word, and the Word was with God, and the Word was God. He was in the beginning with God. (John 1:1-2)
We are told here that Jesus Christ – the Word of God – was “with God” in the beginning. If I said, “I am with my wife,” you would not think I was saying that “I am my wife.” In the same way, we can clearly see a distinction in John 1:1 between the Father and the Son. However, John also tells us that the Word “was God,” so clearly He is the same God while at the same time being a distinct and separate person.
Another text illustrating this truth is Zechariah 12:10.
I will pour out on the house of David and on the inhabitants of Jerusalem, the Spirit of grace and of supplication, so that they will look on Me whom they have pierced; and they will mourn for Him, as one mourns for an only son, and they will weep bitterly over Him like the bitter weeping over a firstborn.
Zechariah speaks here of a time when God will pour out His Spirit, showing that the Spirit of God is a distinct entity. Some cult groups have claimed that the Holy Spirit is not a person but “God’s active force.” However, we can see from other verses that God the Holy Spirit has every aspect of a person: The Spirit loves (Rom 15:30); He is someone you can have fellowship with (2 Cor 13:14); He speaks (Acts 8:29); He can be lied to (Acts 5:3); He can be grieved (Eph 4:30). Clearly these are not attributes of an impersonal force, but of a person.
Notice also in Zechariah 12:10 that God says, “they will look on Me whom they have pierced.” God says it is He who will be pierced on the cross, and then in the next part of the verse He speaks of the one on the cross as somehow different from Him: “and they will mourn for Him.” As in John 1:1, we see here a distinction of persons within the united Godhead.
The Error of Modalism
A common error and false teaching regarding the Godhead is modalism. Also known as Oneness Pentecostalism, modalism is a heresy which wrongly teaches that God is one person that puts on three different “masks.” In other words, the modalist believes that God is one single person that has manifested Himself in three different modes or roles.
Those who adhere to this false doctrine believe that in the Old Testament God appeared as the Father, then in the ministry of Jesus God appeared as the Son, and then after Jesus’ ascension God now operates as the Holy Spirit. This is a denial of the Trinity because it contradicts the clear teaching of Scripture that God is one God in three persons, claiming instead that God is only one person playing three different roles. However, Scripture clearly teaches that God the Father, Son and Holy Spirit are not simply three modes; they are not three masks worn by one person, but they are clearly three distinct persons in one united God.
One helpful verse on this is Matthew 26:39.
And going a little farther [Jesus] fell on his face and prayed, saying, “My Father, if it be possible, let this cup pass from me; nevertheless, not as I will, but as you will.”
In order to hold to the false notion that the Father, Son, and Holy Spirit are all the same person, not only do you have to say that Jesus was praying to himself here, but you have to completely ignore the last part of the verse where Jesus says, “not as I will, but as you will.” This phrase clearly teaches that the Father and the Son have two different wills. They are One God – as Jesus said, “I and the Father are One” (John 10:30) – but they are two distinct persons in the Godhead, each with His own will.
Another text refuting modalism is Matthew 3:16-17, which recounts the baptism of Jesus.
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 can see all three members of the Godhead acting as distinct persons. It would be ludicrous to suggest that Jesus was somehow acting as a ventriloquist here, making a voice sound from Heaven!
And the text immediately after Jesus’ baptism is instructive as well:
Then Jesus was led up by the Spirit into the wilderness to be tempted by the devil. (Matt. 4:1)
Are we supposed to believe, as the modalist claims, that this verse is teaching that Jesus led Himself into the wilderness? Or is the Holy Spirit another person in the Godhead who led Jesus into the wilderness?
So we can see from the above verses (and there are many more) that modalism, or Oneness Theology, is in direct opposition to what Scripture teaches. This denial of the triune Godhead not only results in the worshiping of a God who is different from the God of the Bible (i.e., idolatry), but it also leads to a works-based salvation. Within various groups the works added to salvation may be different, but some examples include: that baptism by full immersion is necessary for salvation; that baptism is invalid unless performed in the name of the Lord Jesus only; and that speaking in tongues is the only sure evidence of salvation.
In response, it should be noted that even though baptism is important and the obedient thing for a believer to do, it is not a work needed to get someone into heaven. The thief on the cross was never baptized. Secondly, the claim that baptism is invalid unless performed only in the name of the Lord Jesus contradicts the teaching of Jesus Himself in Matthew 28:19, where He commands His followers to baptize disciples “in the name of the Father and of the Son and of the Holy Spirit.” Lastly, the claim that speaking in tongues is the only sure evidence of salvation contradicts John 3:16:
For God so loved the world, that he gave his only Son, that whoever believes in him should not perish but have eternal life.
It is not “whoever speaks in tongues” but “whoever believes” that is assured of salvation. In addition, 1 John 5:13 tells us that the book of 1 John was written so that those who profess to believe in Christ can test that their faith is real, and therefore have Biblical assurance of salvation. However, there is no mention of speaking in tongues in 1 John, proving that speaking in tongues is not a Biblical evidence for salvation.
To deny the Trinity is to not worship the God of the Bible as He has revealed Himself. Though the concept that the God of the Bible is one God in three distinct persons may be difficult for us to grasp, it is nevertheless what Scripture plainly teaches. To know this God is to have eternal life (John 17:3); to deny Him is to remain dead in sin (John 8:24).