Three and One
We are to have no other gods (Exodus 20). He is one (Deuteronomy 6). He is our Father (1 Corinthians 8:4-6; 1 Timothy 2:5-6). Jesus is God. His name or title is Emmanuel, meaning “God with us.” He is God (Philippians 2:5-11; Hebrews 1). The Old Testament word Lord is used also in the New Testament to mean YHWH or God (John 20:28). The Holy Spirit is also God (Acts 5:3-4; 1 Corinthians 6:19-20).
Three in One
Biblical descriptions of God point to this logical conclusion. How this functions is a mystery to our limited humanity but some verses help. A married man and woman are one flesh (Genesis 2:24). The Father, Son and Holy Spirit all have one name (28:19-20). The Word, Jesus Christ was God (John 1:1).
Modalism sees God as one person with three modes of being. It is not logical because we find Christ praying to the Father. Tritheism sees God as three Gods. This is also not logical because God is one God, not three Gods. Orthodoxy (right teaching) describes God as one Godhead indivisible and yet three persons.
Christ is God (John 14:9)
Jesus’ own testimony is revealing. He called God’s angels his (Matthew 13:41 cp. Luke 12:8-9, 15:10). He judges the world (Matthew 25:31-46). To know him is to know the Father (John 14:7-9). He claimed to be the resurrection and the life (John 11:25) and made himself equal with God (John 5:18).
John said that “Divine (i.e. God) was the Word” (John 1:1). The author of Hebrews wrote that the Son is an exact representation of God’s nature (Hebrews 1:2-3, 8). Paul called Jesus the image of the invisible God (Colossians 1:15-20), that in him the whole fullness of deity dwells bodily (Colossians 2:9), that he is the judge (2 Timothy 4:1; 2 Corinthians 5:10) and the form of God (Philippians 2:5-11).
The word “Lord” (kyrios) in the Greek Old Testament from New Testament times is the translation of YHWH, meaning God. Often the New Testament word Lord is a quote of an Old Testament reference to God (Acts 2:20-21; Romans 10:13; 1 Peter 3:15). The New Testament uses the word Lord for both the Father and Jesus.
The Holy Spirit is God
The Holy Spirit has personality, personal qualities. He makes determinations or decisions by his will (1 Corinthians 12:11). He teaches (John 14:26; 1 Corinthians 2:11-13). He guides us into all truth (John 16:13). He makes the things of Jesus known to us (John 16:14). He convicts the world of sin (John 16:8). He can be grieved (Ephesians 4:30). He can be blasphemed (Matthew 12:31). He possesses a rational mind (Romans 8:26-27). He can be lied to (Acts 5:3-4). He can be resisted (Acts 7:51). He is distinguished from the Father and the Son (Matthew 28:19-20). We can have fellowship with him (2 Corinthians 13:14).
The Holy Spirit is God. He is neither the Father nor the Son, yet He is spoken of in equal terms to the Father and the Son (2 Corinthians 13:14). He performs the works of God such as: He inspired scripture (2 Peter 1:20-21), regenerates people (Titus 3:5), raised Christ from the dead (Romans 8:11), is eternal (Hebrews 9:14), is omniscient (1 Corinthians 2:10-11) and is called God (Acts 5:3-4 lied to the Holy Spirit = lied to God; 1 Corinthians 3:16; 6:19-20).
The Work of the Holy Spirit
The Holy Spirit was engaged in creation (Genesis 1:2; Job 26:13; 34:14; Psalm 104:29-30; Isaiah 32:15; Romans 8:18-27), the sanctification of Israel (Psalm 51:11; Psalm 143:10; Isaiah 63:10; Nehemiah 9:20; Hebrews 3:7; Isaiah 11:2-5; 32:15-20) and He worked with Old Testament personalities (Numbers 24:2; 1 Samuel 10:6, 10; Ezekiel 2:2), even giving special abilities to some (Exodus 31:1-11; Zechariah 4:6; Nehemiah 9:30; 2 Chronicles 15:1; Genesis 41:38; Numbers 11:17, 25; Deuteronomy 34:9; Judges 3:10; 6:34; 14:19; 1 Samuel 10:10; 16:13; 2 Samuel 23:2; Psalm 51:11; Ezra 1:5).
The Holy Spirit was also vitally involved in Jesus’ ministry on earth (Matthew 1:18; Luke 1:35; Luke 3:21-22; Luke 4:14, 18; Luke 4:1; John 3:34; Matthew 12:28; Hebrews 9:14; Romans 1:4; 8:11; 1 Timothy 3:16; 1 Peter 3:18). He is Called the Spirit of Christ (Isaiah 11:1; 42:1; 62:1; John 15:26-27; Romans 8:9-10) and He works in the Church (Acts 9:31; 20:28; 1 Corinthians 12; Revelation 2:7, 11, 17, 29; 3:1, 6, 13, 22), helps us know what to say (Mark 13:11), gives us spiritual wisdom (1 Corinthians 2:12-13), and encourages us (Acts 9:31).