With regards to the Catholic religion, I find it interesting that their own Justin Martyr held a very different view of the one true God and His Son. In Dialogue With Trypho and (I believe it was) his First Apology it is quite clear that he worshipped Christ as God because He is God's only begotten but that he viewed the Father alone as the one true, unbegotten, ineffable God (above whom there is no other) who at some point in time begat a Beginning, a certain rational power, as fire begets a flame. He also indicates that he considered the Spirit to be none other than the Son Himself. This doesn't fall in line with the idea that God has eternally existed as three distinct persons in one God.
When I brought this up to a certain devout Catholic he said it was ok for Justin not to affirm the Trinity doctrine since it had not been fully formed yet. But that anyone who does not adhere to it today is damned because they do not hold tight to the dogma's of the one true church (my paraphrase). But my point was this: if the Bible is our authority, it should have been evident to Justin, that is, if this doctrine were actually taught in the Scriptures. I'm not sure whether I agree with Justin or not, but I did find it interesting that he is regarded as an early father of the faith yet his view of God is in opposition to the Trinitarian belief.
There is a common misconception that Christian Doctrine was something that was settled at the time of Christ and the writing of the Bible but it was not.
As the Christian community pondered and prayed, these doctrines came to be formulated. Most of the time, the doctrines are a result of heresies that have sprung and were in response to them.
The definitive formulation of the Doctrine of the Trinity was at the Council of Nicea in the 4th Century and this formulation is a result of discussions among bishops of the Catholic Church. Justin Martyr lived in the 2nd century, roughly 200 years before the council so its understandable that the Justin did not have a very clear understanding of the relatinship between Father, Son and Holy Spirit. As a matter of fact the sources of most heresies were priests and bishops as these try to come to a deeper understanding of what the faith means.
Even St Augustine and St Thomas, two shining examples of brilliant minds in the Catholic Church get it wrong as well. That is why we have the magisterium and it is the magiterium that pronounces what is and is not true.
It must also be borne in mind that around about this time, the Canon of the Bible was being set.
This in fact illustrate the strength of the structure of authority within the Church. Not every Tom, Dick and Harry can come up with their own doctrine which is what we see now in the different protestant denominations.