Catechism Q#25: Since there is only one God, (Deu_6:4; Isa_44:6;
Isa_45:5; 1Co_8:4-6) why do you speak of three persons, Father,
Son, and Holy Spirit?
Because God has so revealed Himself in His Word that these three distinct persons are the one, true, eternal God. (Gen_1:2-3 creation; Isa_61:1 - cf. Luk_4:18 the Spirit of Jehovah is upon me; Isa_63:8-10 trinity in history of Israel; Mat_3:16-17 baptism of Jesus; Mat_28:18-19 baptising in the name (singular) of the Father, Son, and H.S.; Joh_14:26 & 15:26 & Gal 4:6 & Tit_3:5-6the H.S. whom the Father will send in my name; 2Co_13:14 benediction) also see Isaiah 48:16.
Colossians 1:12-22, 2:6-10 kingdom, first-born, creator, holds all things together, before all things, headship, forgiveness of sins, the image of the invisible God, Christ = Messiah, Lord = Jehovah, all the fullness of Deity, head over all rule and authority (except the Father 1 Cor 15:27)
Phil 2:5-7 in very nature God... equality with God... made in the likeness of men
John 1:1-3, 14- word was in beginning, was God, creator, became flesh, only-begotten of the father
"I Am" statements: (Ex. 3:14 "I Am that I Am") (John 8:58 Before Abraham was, I Am.") (John 14:6 "I Am the Way the Truth and the Life" - see paper)
"I and the Father are one" (John 10:30) Understood as blasphemy
Son of Man - Title emphasizes humanity, but in the following instances is an allusion to Daniel's pre-existent heavenly man-like being who brings the everlasting kingdom to earth - Dan 7:13, 22 cf. Mk. 8:38, Mt. 16:27, Lk 9:26; Mk 13:26=Mt. 24:30=Lk. 21:27; Mk. 14:62=Mt. 26:64=Lk. 22:69. Jesus used this term instead of "Messiah" because the Jews misunderstood the concept of Messiah and because the "Son of Man" title, although indicating Messiahship, was less familiar and He could infuse it with meaning. (Ladd, Theology of the N.T.)
Son of God (Matt 26:63-64; Lk 22:70 - admission in court 'You say that I am"; John 3:16-18 - Jesus refers to himself as Son of God in 3rd person; John 9:35-37 - Jesus identifies himself as Son of God to the lame man He healed; Also, Jesus accepted the appellation from Satan (Mat 4), demons (Mat. 8), disciples (Matt 14:33), Peter (Mat. 16:16), Nathaniel (John 1:49), Martha (John 11:27), even his Roman executioner (Mat. 27:54)
Messiah (Isa. 9:6 - child is born, son is given, name shall be mighty God, everlasting Father, prince of peace)
"I am the first and last" Rev. 1:17-18 cf. Isa 44:6
I am the Light of the world (John 8:12)
Rev 21:5-9 - The lamb on the throne = Jesus says, "I will be their God"
Accepted worship (Mat 8:2 - leper, Matt 14:33 - disciples in the boat; Matt.15:25 - Canaanite women; Matt. 20:20 - mother of James and John; Mark 5:6 - Gerasene demoniac; John 20:28 - Thomas)
Forgave sins (Mark 2:5)
Gives life (John 5:21 cf. I Sam.2:6; Deut.32:39)
Only one Lawgiver and Judge who is able to save and to Destroy (James 4:12)
Matt 5:21 "You have heard.. but I say to you" Lawgiver on par with God in O.T. law
"Not even the Father judges anyone, but He has given all judgment to the Son that all may honor the Son even as they honor the Father" (John 5:22-23)
“execute judgment” (John 5:27); “save” (Luke 19:10)
Glory "Father, glorify me in your own presence with the glory which I had with you before the world was made (John 17:5) cf Isa 42:8 "My glory I will not give to another"
Called for faith in Himself in order to be saved.
Miracles confirmed His testimony about himself.
Greek "Kurios" - Lord - is used in the N.T. both as the modern-day equivalent of "Mister" but also for the divine name which was considered unutterable after the Exile.
Jesus would have corrected them if they were mistaken. Most of them were martyred for their belief that Jesus is God.
Deity: Called "God" in Acts 5:3-4; Possesses divine attributes of omnipresence (Ps. 139:7-12), omniscience (I Cor. 2:10-11), creating the world (Gen 1:2), and saving (John 3:5-6; Rom 8:9ff; Titus 3:5-7)
Personhood of the Holy Spirit established in scripture:
Grammatically: 3rd person masculine pronoun "he," (I Pet 1:11) and called "comforter (not "comfort"), and placement as a person along with lists of persons (Father, Son, and H.S.)
Personally: attributes of intelligence (I Cor 1:11), will (Spirit does things), affections (grief)