Is the doctrine of the Trinity biblical? Well, that depends on what you mean when you say “biblical.” Does the Bible anywhere contain anything like the Nicene Creed? No. Does the Bible anywhere present a systematic statement of the doctrine of the Trinity using technical theological terms such as homoousios or hypostasis? No. So, if this is what is required in order for the doctrine of the Trinity to be biblical, then no, the doctrine isn’t biblical. But this is not what is required for a doctrine to be biblical.

The Westminster Confession of Faith explains, “The whole counsel of God concerning all things necessary for His own glory, man’s salvation, faith, and life, is either expressly set down in Scripture, or by good and necessary consequence may be deduced from Scripture” (1.6). The doctrine of the Trinity is not expressly set down in Scripture in the technical sense described above, but it is certainly a “good and necessary consequence” of what is expressly set down in Scripture. So, what does Scripture expressly teach?

First, Scripture expressly teaches that there is only one God. There is very little controversy about this proposition among those who accept the authority of Scripture. Almost every page of Scripture testifies to the truth that there is one and only one God. Deuteronomy 4:35 is representative when it says, “To you it was shown, that you might know that the Lord is God; there is no other besides him” (see also Deut. 4:39; 32:39; Isa. 43:10; 44:6–8). The polytheism and idolatry of the nations surrounding Israel are strongly condemned on the grounds that Yahweh is God and that there is no other (Isa. 44:6–20).

Second, Scripture expressly teaches that the Father is God. This claim is also relatively noncontroversial in the history of the church. Jesus speaks of “God the Father” (e.g., John 6:27). Paul speaks numerous times of “God our Father” and “God the Father” (e.g., Rom. 1:7; 1 Cor. 1:3; 8:6; 15:24; 2 Cor. 1:2; Gal. 1:1, 3; Eph. 1:2; 5:20; 6:23; Phil. 1:2; 2:11; Col. 1:2; 3:17; 1 Thess. 1:1; 2 Thess. 1:1, 2; 2:16; 1 Tim. 1:2; 2 Tim. 1:2; Titus 1:4; Philem. 3). So, Scripture is clear that there is one God and that the Father is God.

Third, Scripture expressly teaches that the Son is God. If all that Scripture taught were that there is one God and that the Father is God, there would be little difficulty. A Christian could easily conclude that in the Old Testament this one God was spoken of as Yahweh and in the New Testament He is revealed to be the Father. Things become more complicated, however, because of what the Scripture expressly teaches about the Son, about Jesus the Messiah.