The God of the Bible is Not a Trinity

My opponent claims that "God is one" in a way that indicates he is only one person. Paul said, "Now a mediator is not a mediator of one; but God is one." (Gal 3:20) Pro prefers the Amplified Bible's paraphrase: "There can be no mediator with just one person. But God is only one person." But this is not what Paul said or meant. His point is that a mediator doesn't mediate only "one party," but always mediates between two parties, or two sides, in an agreement, whereas God is only one party to the agreement. I would therefore recommend translations like the following: "Now a mediator involves more than one party; but God is one" (Gal. 3:20 NRSV; NIV; NASB and similar). The other "party" to this agreement was Abraham and his offspring (vv. 16-19), which is a "plural" number of persons, so the number of persons in each "party" to the agreement is not indicated by the word "one" (heis). Further, the Greek word for "person" [prosopon] is not even used in Galatians 3:20, so the Amplified Bible was adding to the word of God. (Prov 30:6) The verse says that "God is one," not that "God is one person." He quotes Thayer who, being a Unitarian, rejected the doctrine of the Trinity; of course he'd agree with Pro. "A.T. Robertson: "One, when masculine, sets forth the idea of the cardinal numeral "one;" when referring to people or BEINGS always the cardinal numeral is implied" (page 186 volume 5; pages 526 and 527, volume 4; page 299 volume 4, Word Pictures of the Greek New Testament)" I agree, God is numerically one "being," but nothing in Galatians 3:20 says he is one "person." Being one being doesn't prove God is not tri-personal. If "person" was the only option given by Robertson Pro would have a good point, but the word isn't limited to persons, it includes beings too. "Kenneth S. Wuest: "The word 'ONE' is masculine in gender, and therefore is personal, referring to a person." (Wuest's word studies from the Greek N.T. vol. 1 pg 106)" Wuest was simply wrong, for "heis" in the masculine gender is applied to non-persons such as "one" of the gates in Revelation 21:21 and "one" loaf in 1 Corinthians 10:17. In Wuest's Word Studies in the Greek New Testament, Vol. 1, we find these comments on Galatians 3:20: "In this verse Paul shows that the promise is superior to the law, for the former was given directly from God to Abraham, whereas the latter was given to Israel by God through a mediator. We will examine the statement, ‘A mediator is not of one.' The word mediator is from mesites, which in turn comes from mesos which means middle, the midst. Thus a mediator is one who intervenes between two, either to make or restore peace and friendship, to form a compact, or to ratify a covenant. The word in the Greek text is preceded by the definite article, making the word generic in character. That is, Paul is not referring here to any particular mediator as Moses, but to the office of a mediator, and to mediators in general looked upon as a class of individuals. However, this generic statement is intended to be applied to Moses, the mediator referred to in verse 19. The word one is masculine in gender, and therefore is personal, referring to a person. That is, a mediator does not act simply in behalf of one person. The very genius of the word implies that the mediator stands "in the midst" of two or more persons, thus acts as a go-between. It is not that the mediator acts in behalf of a plurality of persons that constitute one party [a class action suit], but that there is a plurality of parties between which he acts. Thus the law is a contract between two parties....But the promise of free grace is not in the nature of a contract between two parties. God acts alone and directly when He promises salvation to anyone who will receive it by the out-stretched hand of faith. There are no good works to be done by the sinner in order that he might merit that salvation. Grace is unconditional. There are no strings tied to it. God is One, that is, He acts alone without a mediator in respect to the promise of grace" (pp. 106-107). So his understanding of "one" was that God acts alone without a mediator, not that he is only one person. Pro, do you accept your source's explanation of Galatians 3:20? Wasn't he a Trinitarian? "Marvin Vincent: "the masculine εἶς, one person" (Vincent's Word Studies, Retrieved from E-Sword Electronic Version)" Vincent says: "Now a mediator is not a mediator of one (ὁ δὲ μεσίτης ἐνὸς οὐκ ἔστιν) Observe, 1. Δὲ is explanatory, not antithetic. The verse illustrates the conception of mediator. 2. The article, the mediator, has a generic force: the mediator according to the general and proper conception of his function. Comp. the apostle (Co2 12:12); the shepherd, the good (Joh 10:11). 3. Ἑνὸς of one, is to be explained by the following εἷς, so that it is masculine and personal. We are not to supply party or law. The meaning is: the conception of mediator does not belong to an individual considered singly. One is not a mediator of his single self, but he is a mediator between two contracting parties; in this case between God and the people of Israel, as Lev 26:46; thus differing from Christ, who is called the mediator of a new covenant (Heb 8:6; Heb 9:15; Heb 12:24). The new covenant, the gospel, was not a contract. Accordingly Gal 3:20 serves to define the true conception of a mediator, and through this definition to make clearer the difference between the law, which required a mediator, and the promise, which is the simple expression of God's will. The very idea of mediation supposes two parties. The law is of the nature of a contract between God and the Jewish people. The validity of the contract depends on its fulfillment by both parties. Hence it is contingent, not absolute. But God is one (ὁ δὲ θεὸς εἷς ἀστίν) God does not need a mediator to make his promise valid. His promise is not of the nature of a contract between two parties. His promise depends on his own individual decree. He dealt with Abraham singly and directly, without a mediator. The dignity of the law is thus inferior to that of the promise." (Vincent's Word Studies, 1886 http://www.sacred-texts.com... ) His point was not that God is only one person as Pro asserts, but rather, that he deals directly without a mediator. Pro, can you please give us a full quote and the link to your source? "When the masculine singular "heis" is used, it always refers to one person." Galatians 3:8 says we are all one (heis) in Jesus Christ. The church is many people in one body (1 Cor 12:12-20, 27) Galatians 3:8 uses "heis" (masculine singular) for a group of persons, this refutes Pro's whole argument. The word "only" at John 17:3 doesn't imply that Jesus isn't God because Scripture says Jesus is the true God at 1 John 5:20; it also identifies the Son as God at Hebrews 1:8; John 20:28; 1:1-3, 14. The Father is not only called the Only true God (John 17:3), but also "Only Saviour" (Jude 25) [also see Isa 43:11; 45:21; Hos 13:4]. If "only" at John 17:3 excludes Jesus from being "True God", then Jesus is also excluded from being Savior too. Does Pro therefore deny Jesus as his Savior? As for 1 Corinthians 8:6, if the Father being the "one God" excludes Jesus from being God, then Jesus being the "one Lord" excludes the Father from being Lord. Pro, is the Father also "Lord"? "The Jews reject the Trinity." They also rejected Jesus as their Messiah, along with the entire New Testament canon; truth isn't decided by what the Jew's accept or reject as a nation. Pro, tell us, how many persons are mentioned at John 1:1, one or two? Is each person "God" according to that verse? If so, how many gods is that? One, or are they both included in the one God? I'd be interested to see your take on John 1:1.