For there are three that bear record in heaven, the Father, the Word, and the Holy Ghost: and these three are one.” 1 John 5:7. This is a clear and plain text proving that the Father, Son and Spirit are one God. How can you continue to reject the Trinity in light of this evidence?

Answer:

The text from 1 John 5:7 lists the three and says they are one. The Trinitarian will understand that to mean that they are one God. This is done by supplying the word "god" after "one" when the Bible places a full stop. But this is not what is stated there. The actual verse explains that the "one" applies to the record that is borne, not to the persons of God. They are all one in bearing the same record. From the context of the chapter (the whole epistle even) we learn that John is not expounding on the doctrine of who is God (or how many persons/beings). The immediate context of that passage offers the simple answer. Let us read verse 8 where another "three" are listed:
8 "And there are three that bear witness in earth, the Spirit, and the water, and the blood: and these three agree in one."
The oneness spoken of in this verse does not refer to the nature of the spirit, water and blood. It is rather a oneness in agreement. They are one in that they all bear the same testimony: "agree in one". This is obvious to any reader. This is exactly what John means in verse 7. He uses almost the same words, elaborating more on them in verse 8. "These three" (Father, Word, Spirit) he says, "are one". Not one God (or Godhead, as some call it), as many would like to believe, but ONE IN TESTIMONY. They all agree in giving the one testimony, in bearing one record. This is the plain meaning of the text.
What is that testimony that John seeks to elaborate on in this chapter?
5 "Who is he that overcometh the world, but he that believeth that Jesus is the Son of God?"
10 "He that believeth on the Son of God hath the witness in himself: he that believeth not God hath made him a liar; because he believeth not the record that God gave of his Son."
What is the record that God gave of His Son? What is that record that is testified to in heaven and earth?
What is that record that "these three are one" in bearing? Please notice how the Father, the Word, and the Spirit bear the same record:
The Father testified: Matthew 3:17 "And lo a voice from heaven, saying, This is my beloved Son, in whom I am well pleased."
Matthew 17:5 "While he yet spake, behold, a bright cloud overshadowed them: and behold a voice out of the cloud, which said, This is my beloved Son, in whom I am well pleased; hear ye him."
The Son of God testified: John 10:36 "Say ye of him, whom the Father hath sanctified, and sent into the world, Thou blasphemest; because I said, I am the Son of God?"
The Spirit also testified through the Apostles (John 15:26; 1 John 5:10):
Acts 5:32 "And we are his witnesses of these things; and so is also the Holy Ghost, whom God hath given to them that obey him."
Acts 8:37 "And Philip said, If thou believest with all thine heart, thou mayest. And he answered and said, I believe that Jesus Christ is the Son of God."
Acts 9:20 "And straightway he [Paul] preached Christ in the synagogues, that he is the Son of God."
34 "(and many, many other similar testimonies given by men moved by the spirit of God)"
Therefore, it is not dividing the word of truth correctly when we attempt to use that text to teach that there are three co-equal, co-eternal divine persons or beings. We are also breaking John's testimony when we deny that the Son of God was begotten (John 3:16) of the Father from the days of eternity (Micah 5:2) being so far back in the ages of eternity that it cannot be computed or calculated (7BC 919, ST, May 3, 1899 par. 4). To teach 3 co-equal, co-eternal beings is to deny the Father-Son relationship. It is to deny that Jesus is the Son of the living God, reducing that noble and ineffable relation to a mere metaphor and role-play! People who use this text to teach a trinity (denying the Son of God) only serve the purpose of obliterating the testimony that heaven is trying to reveal to us!
Now, having answered the verse plainly from the Bible, allowing the Bible to interpret itself, let us have a look at what some Bible commentaries say regarding this verse: "The disputed words found their way into the KJV by way of the Greek text of Erasmus. It is said that Erasmus offered to include the disputed words in his Greek Testament if he were shown even one Greek MS that contained them. A library in Dublin produced such a MS (known as 34), and Erasmus included the passage in his text. It is now believed that the later editions of the Vulgate acquired the passage by the mistake of a scribe who included an exegetical marginal comment in the Bible text that he was copying. The disputed words have been widely used in support of the doctrine of the Trinity, but, in view of such overwhelming evidence against their authenticity, their support is valueless and should not be used. In spite of their appearance in the Vulgate, A Catholic Commentary on Holy Scripture freely admits regarding these words: "It is now generally held that this passage, called the Comma Johanneum, is a gloss that crept into the text of the Old Latin and Vulgate at an early date, but found its way into the Greek text only in the 15th and 16th centuries." (Thomas Nelson and Sons, 1951, p. 1186)" (The Seventhday Adventist Bible Commentary, vol. 7, p. 675)