I've read the article you posted, so I will read what you come up with.
Regarding the article, I cross checked all the verse the author presented. While his commentary is mostly true, the scriptural references fall short because even the author had to supplement scripture with Tradition in an attempt to explain the Trinity. And it's ok. Scripture doesn't claim to contain all truths a Christian must believe.
I'll restate the 3 doctrines I posted a page or 2 back for ease.
1. That the Father, Son and holy Spirit have one nature or substance.
2. That They have one power and authority.
3. That there is a consubstantial Trinity, one Deity to be adored in three subsistences or persons.
Every Christian acknowledges these 3 truths. Please quote book, chapter, verse of scripture that teaches them.
@Watchman1 just joined the conversation. Maybe he can help?
Even though the Trinity is not overtly set out as a hard and fast doctrine in the Bible, there are passages in the Bible that clearly show it. At the baptism of Jesus, we have Jesus being baptised, the voice from heaven saying, "This is my beloved Son", and the Holy Spirit in visible form, like (but not) a dove coming down and resting on Him. Because we know that the Holy Spirit is a real Person whom we recognise as God, then it is obvious that there are three entities at that baptism. Whose is the voice from heaven if not the Father's? We have the same happening at the transfiguration of Jesus. There's Jesus with Elijah and Moses, and the voice from heaven saying, "This is my beloved Son. Hear Him." In the Garden of Gethsemane, Jesus prayed to the Father. We are also told by Jesus that when He was to leave the earth, He will send the Holy Spirit to represent Him. Then He went and offered His blood to the Father in the heavenly holy of holies.
So, when one uses his intelligence when reading the Scriptures, one sees that there are definitely three entities: one recognised as the Father, who is a spirit invisible to everyone, another recognised as the Son who came to our world as Jesus Christ, and still another the Holy Spirit who has shown to have a voice of His own, for example in Acts where He called Paul and Barnabas to the work He had prepared for them.
To say that there is no Trinity, and that there is only one God, defies simple intelligence when reading what the Bible actually says. Or like the Oneness people who say that God shows Himself in three different modes. When we view Jesus' baptism and transfiguration, we see the stupidity of that, because we see the Father who spoke from heaven and Jesus being right there for all to see. So in these cases, you can't have a God who manifests in two or more modes at once. And when Jesus went off the pray to the Father, how can one mode pray to itself? One would have to be a total dufus to believe in modalism.
We are not told directly about the substance of God, but we do know that the Father, Son, and Holy Spirit are totally unified in nature, character and mission, and that it was the Father who sent Jesus to the world, and it was Jesus who sent the Holy Spirit to indwell believers. Jesus did what the Father told Him, and the Holy Spirit does what Jesus has told Him, making the three of them say exactly the same thing, so it doesn't matter how God speaks to us, we can know that the Father speaks, the Son speaks, and the Holy Spirit speaks. and so no matter who speaks to us, we can rightly say, "God told me".