### God is one being, and he exists as the Holy Trinity, that is, as the Father, the Son, and the Holy Spirit
#### The Bible teaches that there is only one God.
In the Old Testament:
>Yahweh, he is God, and there is no other God!! (1 Kings 8:60 ULB)
In the New Testament:
>Jesus said,... "This is eternal life: That they know you, the only true God". (John 17:3 ULB)
(See also: Deuteronomy 4:35, Ephesians 4:5-6, 1 Timothy 2:5, James 2:19)
#### The Old Testament begins to reveal God's three persons.
>God created the heavens ... The Spirit of God was moving ... "Let us make man in our image." (Genesis 1:1-2, 26 ULB)
>But in these last days, he has spoken to us through a Son, whom he appointed to be the heir of all things. ... But to the Son he says, "Your throne, God, is forever and ever. The scepter of your kingdom is the scepter of justice. ... In the beginning, Lord, you laid the earth's foundation. The heavens are the work of your hands." (Hebrews 1:2, 10 ULB, quoting Psalm 45:6; 102:25)
#### The Church has always found it necessary to state what the New Testament says about God by affirming that he exists in three distinct persons: The Father, the Son, and the Holy Spirit.
>Jesus said, "...Baptize them into the name of the Father, of the Son, and of the Holy Spirit." (Matthew 28:19 ULB)
>God sent out his Son, born of a woman ... God has sent into our hearts the Spirit of his Son, who calls out, "Abba, Father." (Galatians 4:4-6 ULB)
See also: John 14:16-17, 1 Peter 1:2
Each person of God is fully God and is called "God" in the Bible.
>Yet for us there is only one God, the Father ... (1 Corinthians 8:6 ULB)
>Thomas answered and said to him, "My Lord and my God." Jesus said to him, "Because you have seen me, you have believed. Blessed are those who have not seen, and believed." (John 20:28-29 ULB)
>But Peter said, "Ananias, why has Satan filled your heart to lie to the Holy Spirit and to keep back part of the price of the land?... You have not lied to men, but to God." (Acts 5:3-4 ULB)
Each person is also distinct from the other two persons. All three persons can appear separately at the same time. In the verses below, God the Son is baptized while God the Spirit comes down and God the Father speaks from heaven.
>After he was baptized, Jesus came up ... from the water.... He saw the Spirit of God coming down ... and a voice [the Father's] came out of the heavens saying, "This is my Beloved Son...." (Matthew 3:16-17 ULB)