How do we know that the doctrine of the Trinity is biblical? That the Trinity is a biblical doctrine can be seen from five simple statements supported by the Bible. And, since the Jehovah’s Witnesses are one group so adamantly opposed to the doctrine as being something "pagan," "unreasonable," and "of the devil," we thought it might be instructive to begin by citing their own Bible, the New World Translation (1970 edition), in support of the doctrine. Thus, even the New World Translation teaches the doctrine of the Trinity. In the scriptures below, the term "Holy Spirit" is not capitalized because Jehovah’s Witnesses believe that "holy spirit" is merely God’s active, impersonal force, not a true person. (For those who have never done so, looking up these scriptures during your time of personal Bible study will be a rewarding learning process.)

1. There is only one true God: "For there is one God, and one mediator between God and men" (1 Tim. 2:5 NWT; cf. Deut. 4:35, 6:4; Isa. 43:10).

2. The Father is God: "There is actually to us one God the Father" (1 Cor. 8:6 NWT; cf. John 17:1-3; 2 Cor. 1:3; Phil. 2:11; Col. 1:3; 1 Pet. 1:2).

3. Jesus Christ, the Son, is God: "but he [Jesus] was also calling God his own Father, making himself equal to God": (John 5:18 NWT); "In answer, Thomas said to him [Jesus]: ‘My Lord and my God!’" (John 20:28 NWT, cf. Isa. 9:6; John 1:1; Rom. 9:5; Titus 2:13; 2 Pet. 1:1).

4. The Holy Spirit is a person, is eternal, and is therefore God: "However, when that one arrives, the spirit of the truth, he will guide you into all the truth, for he will not speak of his own impulse, but what things he hears he will speak and he will declare to you the things coming" (John 16:13 NWT, emphasis added). The Holy Spirit is also eternal: "How much more will the blood of the Christ, who through an everlasting spirit offered himself without blemish to God" (Heb. 9:14 NWT). The Holy Spirit is therefore God: "But Peter said: ‘Ananias, why has Satan emboldened you to play false to the holy spirit?’ You have played false, not to men, but to God" (Acts 5:3, 4 NWT, emphasis added).

5. The Father, Son, and Holy Spirit are distinct Persons with equal authority: "Baptizing them in the name of the Father and the Son and of the Holy Spirit"; "Now I exhort you, brothers, through our Lord Jesus Christ and through the love of the spirit, that you exert yourselves with me in prayers to God for me"; "The undeserved kindness of the Lord Jesus Christ and the love of God and the sharing in the holy spirit be with all of you" (Matt. 28:19; Rom. 15:30; 2 Cor. 13:14 NWT).

In Scripture, the Father, the Son, and the Holy Spirit are clearly distinguished as separate persons, yet there is only one God. Thus, "There is... one Spirit... one Lord [Jesus]... one God and Father of all" (Eph. 4:4-6; cf., 1 Cor. 12:4-11). Further, the Father, Son, and Holy Spirit are never identified as one person only, as modern modalists such as the United Pentecostal Church/ "Jesus Only" groups teach. For example, in John 6:38 (KJV) Jesus says, "I came down from heaven, not to do mine own will, but the will of Him that sent me." Because will is the essence of personality, we certainly have two personalities here.

In addition, the Father, Son, and Holy Spirit are so dearly and consistently linked in Scripture that to assume God is not three Persons makes it impossible to understand some passages. For example, consider the following Scriptures:

(See also Rom. 14:17,18; 15:13-17; 1 Cor. 6:11,17-19; 2 Cor. 3:4-6; Gal. 2:21-3:2; Eph. 5:18-20; Phil. 2:1,6; Col. 1:6-8; 1 Thess. 1:1,5; 4:2,8; 2 Thess. 3:5; 1 John 3:23,24.)

To further illustrate, try answering the following questions without concluding that the Bible teaches the doctrine of the Trinity: