There is one God who exists in three Persons – the Father, the Son, and the Holy Spirit – each of whom is equal with respect to their Divinity.
(1) There is only one God (Deuteronomy 6:4, Isaiah 45:21-22, I Cor. 8:4).
(2) The Father is God, the Son is God, and the Holy Spirit is God.
(A) The Father is God (I Peter 1:2; John 6:27, 20:17; Galatians 1:1; Matthew 11:25; Jude 1).
(B) The Son — or Word — is God (John 1:1, 8:58, 20:28; Hebrews 1:1-8).
(C) The Holy Spirit is God (Acts 5:1-11; I Corinthians 2:11; 6:19-20).
(3) The Father is a Person, the Son is a Person, and the Holy Spirit is a Person.
(A) The Father is a Person. We can have fellowship with him, 1 John 1:3; he knows, Matthew 6:6-8; he teaches, Matthew 16:17; he loves, John 16:27; he is a witness, John 8:18.
(B) The Son is a Person. We can have fellowship with him, 1 John 1:3; he knows, Matthew 11:27; he teaches, John 1:18, Rev. 2:18; he loves, Romans 8:35, Gal. 2:20; he is a witness, John 8:18; he can be grieved, John 11:35.
(C) The Holy Spirit is a Person. We can have fellowship with him, Philippians 2:1, II Cor. 13:14; he knows, I Cor. 2:11; he teaches, Luke 12:12, I Cor. 2:13; he loves, Romans 15:30; he is a witness, Acts 20:23, Romans 8:16; he can be grieved, Ephesians 4:30.
(4) The Father, the Son, and the Holy Spirit are personally distinct from one another.
The Father, the Son, and the Holy Spirit are able to:
(A) Send or be sent by one another (John 3:17, 10:36, 14:23-26, 15:26, 16:7).
(B) Speak to each other (John 17:1-26, Romans 8:26-27, Hebrews 1:7-8) and about each other (Matthew 17:5, Mark 1:11, John 8:13-18).
(C) The Father and Son love and honor each other (John 3:35, 5:20, 14:31).
The Trinity doctrine — that there is one God in three Persons — summarizes these biblical truths without adding or subtracting anything from them.
Although the Father, Son, and Holy Spirit are personally distinct from one another, they are not separate from one another as human persons are. This truth can be gleaned by the discerning student from such passages as John 14:9 and 1 Corinthians 2:11.
This is the doctrine I will be defending on this website.