Systematic Theology: God is the Sovereign Creator and Sustainer of All Things [7], and God is Triune

[The following is edited from material that I originally put together for a devotional group that met before our shift, when I worked at UPS. The meeting where we were focused on the Trinity took place in June 2010. Some of the guys who met for that group were from Muslim backgrounds, so I thought consideration of the Trinity was especially important.]

Summary of the biblical doctrine of the Trinity:

Within the one being that is God, there exists eternally three co-equal and co-eternal Persons: namely, the Father (Matt 6:9), the Word or Son (John 1:1-2; 17:5; Col 2:9), and the Holy Spirit (John 14:26; 15:26; Acts 8:29; 13:2), each with distinct personal attributes (Isa 48:16; Matt 3:16-17; Rom 8:26-27; Heb 9:13-14), but without division of nature, essence or being (John 10:30; 14:9; Acts 5:39).

Examples of Triadic passages:

Matt. 28:18-19
II Cor. 13:14

Origin of the doctrine of the Trinity:

C.S. Lewis notes that the Church’s understanding of the Trinity first started to become clear due to the experiences of Jesus’ early followers: The disciples knew of God in a vague way, they met Jesus Christ, and they found God living in them (i.e., the Holy Spirit).

Similarly, Bruce Ware notes that the Church’s understanding of the Trinity first started to become clear due to the Person and Work of the Lord Jesus Christ: The nature of Jesus’ claims and His actions verifying those claims drives us to the inevitable conclusion of His deity [see Mark 2:1-12], yet He is shown as distinct from the Father by His prayers and human nature.

Biblical evidence of the Trinity:

Our knowledge of God comes from what He has revealed about Himself in Scripture.
We know that the Father and the Son [also called God and the Word] are two distinct Persons, yet one God, due to Bible passages such as John 1:1. In John 1:1, we see:

1. The Word was with God: language describing a face-to-face relationship (indicating intimacy and distinction).
2. The Word was God: language indicating identity.

The Old Testament focuses on the LORD as one in His being, as we see from passages like Deuteronomy 6:4, though the Old Testament also points forward to Jesus Christ by prophesies and types. The New Testament focuses on the Person of Jesus Christ. Therefore, we have less direct information about the Holy Spirit. But we do see that the Holy Spirit is considered a distinct Person– in Matt. 28:18-19 and II Cor. 13:4 as already noted, and in passages such as John 14:26 and 16:7, which are extremely important for other theological reasons as well– and He is considered to be God, as we see, for example, in a comparison between passages such as I Cor. 2:11 and Rom. 11:33-34.

The importance of the doctrine of the Trinity:

We must believe in God as He has revealed Himself to us, not inventing a God from our own imaginations, for that would be idolatry. Though non-Trinitarian presentations of God sometimes seem to make sense considered in themselves, the doctrine of the Trinity is the only understanding of God that reflects all the Bible has to say concerning the nature of God. The doctrine of the Trinity is not something that could have arisen based on human reasoning alone; we only know God as Triune based on what He has revealed. And so the doctrine of the Trinity, properly understood, drives us to faith in His Word.