The Bible clearly teaches that we have one God. The Old Testament declares, "Hear, O Israel: The Lord our God, the Lord is one." (Deuteronomy 6:4) It also declares, "I am the Lord, and there is no other; apart from me there is no God." (Isaiah 45:5) The New Testament agrees, "There is no God but one." (1Corinthians 8:4 All quotations are from the NIV.)
And yet, the Bible also refers to God as three persons, such as in the Great Commission, "Therefore go and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit." (Matthew 28:19)
The clearest example of the threefold nature of God is when Jesus was baptized. "As soon as Jesus was baptized, he went up out of the water. At that moment heaven was opened, and he saw the Spirit of God descending like a dove and alighting on him. And a voice from heaven said, 'This is my Son, whom I love; with him I am well pleased.'" (Matthew 3:16-17. Also Mark 1:10-11, Luke 3:21-22) So, God the Father spoke from Heaven as God the Holy Spirit descended in the form of a dove onto God the Son, Jesus.
One way to help understand how one God can be three Persons is to think of an egg. It has three parts: shell, white and yolk, but it is one egg.
Christians historically refer to the Father, the Son and the Holy Spirit as the Trinity. But "Trinity" does not quite describe God correctly. Some people think "Trinity" means that we worship three gods. A better name is "Triune God" or "God the Three in One."
The Old Testament mostly teaches about God as One, but there are a few evidences of the Triune nature of God. The Holy Spirit is mentioned in Psalm 53:11 and Isaiah 63:10-11. The Spirit of God came upon many of the Judges as they led the nation of Israel: Othniel (Judges 3:10), Gideon (6:34), Jephthah (11:29) and Samson (13:25, 14:6, 14:19, 15:14)
Also, the Son must have appeared to Abraham. We know this because God told Moses, "You cannot see my face, for no one may see me and live." (Exodus
33:20) But the Old Testament also says, "The Lord appeared to Abraham near the great trees of Mamre." (Genesis 18:1a) God must have appeared to
Abraham as God the Son, because Abraham would have died if he had seen God the Father.
Jesus spoke about meeting with Abraham to Jews in Jerusalem. He said, "Your father Abraham rejoiced at the thought of seeing my day; he saw it and was glad.'
'You are not yet fifty years old,' they said to him, 'and you have seen Abraham!'
'Very truly I tell you,' Jesus answered, 'before Abraham was born, I am!' At this, they picked up stones to stone him, but Jesus hid himself, slipping away from the temple grounds." (John 8:56-59)
The people were ready to stone Jesus for blasphemy, because He claimed to be God. He referred to himself with the sacred name of God, "I AM WHO I AM," revealed by God to Moses at the burning bush. (Exodus 3:14) Jesus not only claimed that he existed before he was born as a baby in Bethlehem, but he also revealed that he is the eternal "I AM," just like God the Father.
John declared the eternal nature of Jesus, the Word, at the beginning of his gospel, "In the beginning was the Word, and the Word was with God, and the Word was God. He was with God in the beginning. Through him all things were made; without him nothing was made that has been made." (John 1:1-3)
Also, the night before he died, Jesus prayed to God the Father, "I have brought you glory on earth by finishing the work you gave me to do. And now, Father, glorify me in your presence with the glory I had with you before the world began." (John 17:4-5)
These Bible passages teach us that Jesus the Son existed long before he was born in Bethlehem. Jesus was not only present at the beginning of all creation, but he participated in the creation of all things.
Even while Jesus was a human, he still kept the nature of God. Jesus said, "I and the Father are one." (John 10:30) He told his disciples, "Anyone who has seen me has seen the Father." (John 14:9) The writer of Hebrews wrote, "The Son is the radiance of God's glory and the exact representation of his being, sustaining all things by his powerful word." (Hebrews 1:3) John wrote, "No one has ever seen God, but the one and only Son, who is himself God and is in closest relationship with the Father, has made him known." (John 1:18) Paul wrote, "The Son is the image of the invisible God, the firstborn over all creation." (Colossians 1:15)
After Jesus rose from the dead and returned to heaven, God the Father restored his former glory, and highly exalted him. "Therefore God exalted him to the highest place and gave him the name that is above every name, that at the name of Jesus every knee should bow, in heaven and on earth and under the earth, and every tongue acknowledge that Jesus Christ is Lord, to the glory of God the Father." (Philippians 2:9-11)
Now that Jesus is back in heaven, he has a different task: interceding with the Father for us. "For there is one God and one mediator between God and mankind, the man Christ Jesus, who gave himself as a ransom for all people." (1Timothy 2:5-6) "Who then is the one who condemns? No one. Christ Jesus who died-more than that, who was raised to life-is at the right hand of God and is also interceding for us." Romans (8:34) Could we ask for a better intercessor and mediator than the one who gave his life for us?