Explain the Trinity

Scripture tells us that God is one: “Hear, O Israel! The LORD is our God, the LORD is one!” (Deuteronomy 6:4). At the same time, God is also Three Persons: Father, Son and Holy Spirit. For example, we see this truth evident in several chapters in Isaiah (Isaiah 6, 9, 42, 48, 63), and even in Genesis 1:26.

While we cannot fully comprehend the Trinity in this life, Scripture clearly teaches that God is three Persons in the Father, the Son, and the Holy Spirit, yet is also One God. Scripture will also, at times, refer to the Persons of the Trinity interchangeably. An example is the “Spirit of Christ” (Romans 8:9, 1 Peter 1:11), which clearly refers to Jesus and the Holy Spirit as One. Jesus even says that He and the Father are One (John 10:30). How is this possible? Again, we don’t know, but we will all know when we meet our glorious God in heaven.

As far as the differences between each person of the Godhead (Father, Son, and Holy Spirit), Scripture does show some different roles played by each person. For example, God the Father is active in the election of believers (e.g., Romans 9). God the Son is the person who reconciles us to the Father by His death and resurrection, and by His imputed righteousness (e.g., Romans 4-5). God the Holy Spirit makes us spiritually alive (Ephesians 2). So, we are chosen by the Father, reconciled through the Son, all by the Spirit. Ephesians 2:18 says it best: “for through Him [Jesus] we both have our access in one Spirit to the Father.”

Much more could be said about God’s Trinitarian nature, as books have been written on this subject. One we would recommend is by John Owen, entitled Communion with the Triune God.

Those who claim to be Christian yet deny that the Trinity or that Jesus is the Son of God are not, by definition, Christians. Jesus tells us this very plainly in Luke 10:16, “The one who listens to you listens to Me, and the one who rejects you rejects Me; and he who rejects Me rejects the One who sent Me.” 1 John 2:23 also makes this clear: “Whoever denies the Son does not have the Father; the one who confesses the Son has the Father also.” By denying that Jesus is the Son, one denies the Son. If one denies the Son, he also denies the Father, and therefore, cannot be a Christian.

Finally, all true Christians believe that Jesus is God. Over and over again, Scripture refers to Jesus as God. Isaiah 9:6 prophesies about Jesus, calling Him God: “For a child will be born to us, a son will be given to us; And the government will rest on His shoulders; And His name will be called Wonderful Counselor, Mighty God, Eternal Father, Prince of Peace.” (Note also that this is a reference to the Trinity, since the New Testament refers to the Holy Spirit as the Counselor.) Thomas calls Jesus God in John 20:28. Paul says of Christ in Titus 2:13, “looking for the blessed hope and the appearing of the glory of our great God and Savior, Christ Jesus.” For the same reasons mentioned above, if one denies that Jesus is God, he is, by definition, not a Christian.