The NT Language is Incompatible with the Doctrine of the Trinity

The Spin

James White, The Forgotten Trinity:

"As long as we can recognize that the word 'God' refers to 'Father, Son & HS' or to all three Persons at once." [p 71.]

"The word 'God' can be used more generically of the [Trinitarian] Godhead in total." [p. 91]

The Truth

The NT says that “God is One Person” [Gal 3.20; Jam 2.19, theos eis estin. Note that when the masculine form of “one” (eis) is used the meaning is “one person”.

 

For example, Paul in Romans 5:19:

“For just as through the disobedience of one person the many were made sinners, so through the obedience of one [Jesus] the many will be made righteous.”

Paul uses the same word “one” (eis) to refer to Jesus. The meaning is of course “one person,” “a single person.”

Same in 1Tim 2.5 when Paul says that for us Christians, “there is one God, and there is one mediator between God and men, the man Christ Jesus”.

In each case God is one Person. That is, the "one God" is contrasted with the "one mediator", Jesus, of course only one person.

Also, Galatians 3:20:

“Now a mediator is not for one party only; whereas God is only one.”

The same Greek word in both halves of the sentence eis, means “one person.” Thus, the Amplified Version catches the meaning:

“God is only one person.”

Furthermore, the Greek phrase eis theos, “God is one [person],” appears several times in the NT:

“‘Well said, teacher,’ the man replied. ‘You are right in saying that God is one and there is no other but him’” (Mark 12:32). 

“There is only one God and there is only one way of being accepted by him. He makes people right with himself only by faith, whether they are Jews or Gentiles” (Rom. 3:30). 

“For there is one God, and there is one mediator between God and men, the man Christ Jesus” (1 Tim. 2:5).

In each case God is not more than One Person.

This pervasive fact of the New Testament is incompatible with the later doctrine of the Trinity that the word "God" means "Father, Son, & Holy Spirit."

Further rules of NT Greek Grammar 
The Greek of the NT speaks of God and Jesus as “one thing.” En, the neuter form of eis meaning one, is the word found in John 10:30. As opposed to the masculine form of “one” (eis) meaning “one person.”

This elementary point was noted in a discussion of the Trinity in a 19th century work by Rev. Richard Treffry:

“‘I and my Father are one’; en in the neuter, one substance [thing]; not eis in the masculine, one person.”

The same is said by modern, textual critical scholars like Bruce Metzger, Lexical Aids to the New Testament:

“In the masculine, eis must be distinguished from the neut. hen. Eis means one numerically while hen means one in essence, as in John 10:30…Had it said eis, it would have meant one person.”

So Who is this One God?

For Jesus & Paul God is the Father, par excellence!

John 17.3; 5.44; 20.17; Rom 1.7; 15.6; 1Cor 1.3; 8.6; 15.24; 2Cor 1.2; 11.31; Gal 1.1-4; 4.6; Eph 1.2-3, 17; 4.6; 5.20; 6.23; Phil 1.2; 2.11; 4.20; Col 1.2-3; 3.17; 1Thess 1.1; 3.11, 13; 2Thess 1.1-2; 2.16; 1Tim 1.2; 2Tim 1.2; Titus 1.4; Phil 1.3.

Compare this with the Old Testament: 

Deut 32.6; Jer 3.19; 31.9; Isa 63.16; 64.8; 1Chron 29.10; Mal 1.6; 2.20; Pro 3.12; Ps 103.13.

Dr. John Hey, Lectures in Divinity, Vol. 2, pp. 249-251:

“When it is proposed to me to affirm that ‘in the unity of the Godhead there be three persons, of one substance, power and eternity: the Father, the Son and the Holy Ghost,’ I have difficulty enough! My understanding is involved in perplexity, my conceptions bewildered in the thickest darkness. I pause, I hesitate. I ask what necessity there is for making such a declaration… But does not this confound all our conceptions, and make us use words without meaning? I think it does. I profess and proclaim my confusion in the most unequivocal manner. I make it an essential part of my declaration. If I pretended to understand what I say, I might be a Tritheist or an infidel. But I could not both worship the one true God, and acknowledge Jesus Christ to be the Lord of all."