I guess that I'll throw myself to the wolves here, even though I know I am unlikely to change hearts and minds. I believe that there is sound biblical basis for the Trinity, I believe that all of the apostles had a firm understanding of God's triune nature, also. I will give my examples all quoted from the King James version of the Bible (italics for emphasis):
Genesis 1:2 'And the earth was without form, and void; and darkness was upon the face of the deep. And the
Spirit of God moved upon the face of the waters.' This passage demonstrates oneness of God with the Holy Spirit.
Isaiah 61:1 'The
Spirit of the Lord GOD is upon me; because the LORD hath anointed me to preach good tidings unto the meek; he hath sent me to bind up the brokenhearted, to proclaim liberty to the captives, and the opening of the prison to them that are bound.' Also demonstrates God's oneness with the Holy Spirit.
Matthew 3:16-17 'And
Jesus, when he was baptized, went up straightway out of the water: and, lo, the heavens were opened unto him, and he saw the
Spirit of God descending like a dove, and lighting upon him: And lo a voice from heaven, saying,
This is my beloved Son, in whom I am well pleased.' This passage clearly demonstrates the Holy Spirit speaking with the voice of God the father in approval of Jesus his Son demonstrating the community and diversity of the Trinity.
Matthew 28:19-20 'Go ye therefore, and teach all nations, baptizing them in the name of the
Father, and of the Son, and of the Holy Ghost: Teaching them to observe all things whatsoever
I have commanded you: and, lo,
I am with you always, even unto the end of the world. Amen.' Jesus clearly speaking of Himself in plurality.
1 Corinthians 8:6 'But to us there is but one God, the Father, of whom are all things, and we in him; and one Lord Jesus Christ, by whom are all things, and we by him.' Paul clearly placing equality in God the Father and Christ the Son and giving plurality to their oneness.
Acts 5:3-4 'But Peter said, Ananias, why hath Satan filled thine heart to lie to the
Holy Ghost, and to keep back part of the price of the land? Whiles it remained, was it not thine own? and after it was sold, was it not in thine own power? why hast thou conceived this thing in thine heart?
thou hast not lied unto men, but unto God. The Holy Spirit here clearly is the same as God.
John 17:21-22 'That they all may be one; as thou, Father, art in me, and I in thee, that they also may be one in us: that the world may believe that thou hast sent me. And the glory which thou gavest me I have given them; that they may be one,
even as we are one' Jesus' words, not mine.
As to the question of how Christ can be truly God and truly man:
John 1:3 'All things were made by him; and without him was not any thing made that was made.' Christ clearly as the Agent of Creation; thus God.
John 4:42 'And said unto the woman, Now we believe, not because of thy saying: for we have heard him ourselves, and know that this is indeed the Christ, the Saviour of the world.' Kind of speaks for itself I think
Acts 10:42 'And he commanded us to preach unto the people, and to testify that it is he which was ordained of God to be the Judge of quick and dead.' Jesus will be the final judge of mankind, thus making him God.
John 8:58 'Jesus said unto them, Verily, verily, I say unto you, Before Abraham was, I am.' Jesus himself claiming to be God. Either he was who he said he was, or he was a madman. No middle ground here for me.
John 17:5 'And now, O Father, glorify thou me with thine own self with the glory which I had with thee before the world was.'
John 10:30 'I and my Father are one.' Self explanatory
John 5:18 'Therefore the Jews sought the more to kill him, because he not only had broken the sabbath, but said also that God was his Father,
making himself equal with God.' The Jews understood the implication of such a claim, why do we question it 2000 years later?
Philippians 2:6-8: 'Who, being in the form of God, thought it not robbery to be equal with God: But made himself of
no reputation, and took upon him the
form of a servant, and was made
in the likeness of men: And being found in
fashion as a man, he humbled himself, and became obedient unto death, even the death of the cross.' This is the clear demonstration of Jesus being both wholly God and wholly man.
John 14:9 'Jesus saith unto him, Have I been so long time with you, and yet hast thou not known me, Philip?
he that hath seen me hath seen the Father; and how sayest thou then, Show us the Father?' Again, either Jesus was who he said he was, or he was mad.
Mark 9:37 'Whosoever shall receive one of such children in my name, receiveth me: and whosoever shall receive me, receiveth not me, but him that sent me.'
When I think of the triune nature of God, being 3 in personhood, 1 in essence, I have some admittedly flawed comparisons, but comparisons worthy of thought. I first think of a fertilized embryo, a father and mother copulating, and at that moment of fertilization, that embryo is 3 persons at the same time (father, mother, and child) while being a single thing. Another admittedly flawed comparison would be an egg, it is one single thing, with three distinct parts, shell, white, and yolk. Also water, which while 1 in essence, can be solid, liquid, and gas.
I am probably approaching my character limit so I'll end here. Let the debate begin
