Incorrect. Prove it. There is no religion in the world, history or otherwise that has anything like the doctrine of the Trinity. People make this assertion quite regularly but as soon as they start producing their so-called earlier Trinities, the difference very quickly becomes apparent.
You are not completely wrong in this statement. At the time of it's official conception, the Trinitarian doctrine in Nicaea, the Catholic church still had many members believing in God and Jesus as Christ. So for them to completely turn God into a Triune God overnight and to make it so apparent, would be disastrous. So they had to twist certain doctrines to still sound Biblical and appease the pagan masses too.
For instance, look at the Vedic god system. There are thousands of gods in their system. But the main three are Brahma, Vishnu and Shiva a triune God.
How about the Greek mythology? Dionysus was a God of wine (Jesus turned water into wine), he was born of an earthly mother and a divine father (Zeus). He was also followed by bands of people and later lamented at his death.
How about the Egyptian concept of Gods? Did you know their idea of a spirit of a man (ba) is depicted as a bird? Don't we see many depictions of God the Holy Ghost as a bird due to the vision of John the Baptist?
Point is, there are a lot of correlations you can make with the biblical Jesus with other Pagan deities of the time and area and to tell a pagan that the biblical God is just like their own would not be a stretch when you can drum up an idea like the trinity.
The Trinity - as in the Word Trinity - is not mentioned in the Bible. So what? That would be an argument from silence.
Point taken.
Yet the concept of the Trinity is inherent from the Creation through to the last page of the NT. The early Christians did argue over the concept. They needed to grapple with the truth that there is ONE GOD as the Deuteronomy passage articulates and then they needed to grapple with the person Jesus. It also became clear during these discussions that the Holy Spirit was not the Father nor was he the Son. Some people suggest he was just a power. Not a personality. Although Jesus made it clear that the Holy Spirit was a person and had a personality. You can't grieve a power. You can't lie to a power. Yes, both of these terms could just be anthropomorphisms. And yet the Church determined otherwise.
For one, which "church" decided this? Have you read the early church fathers? Keep in mind also that the victor of war gets to write the history. The catholic has always tried to say that their church was the first and Peter the first pope. They tried (in vain) to wipe out the history of a true church throughout history. There a snippets here and there where "Oneness" people thrived before the Catholics tried to do away with them. In fact, the church at Rome was Oneness until about 200 A.D. You will find a little paper trail from one popular catholic father to another before Constantine that is quite a tangled web. Pretty interesting actually.
I do believe the reference of the Holy Ghost is God's use of power. See it with every scripture that it is used, such as the overshadowing of Mary. She was found to be child of the Holy Ghost. This would mean that God the Father would NOT be the father in the simplest sense. But if we see the spirit of God working in situations, then it's easy to understand John chapter 14 and how Mary would be found child by the power of God.
Also, you will never find in the old testament a reference of God being with anyone else or there being a multiplicity of Gods that are worth serving.
The Trinity was around before the Roman Catholic Churches. It was not their invention.
True again. The concept of a Trinity was around before the church ever began, but later integrated into the dogma, per my post above with Mall and you.
Also, for reference, when I mention the Catholic church, I am not referring to the official Catholic church as I understand it was not truly formed for hundreds of years after Christ, but the Catholic church did come this ground work, so I use it as a way to delineate the true church and the false church.