What politics were implemented to accomplish the Christian tradition and try to keep what is written in the Holy Bible?

Question: What politics were implemented to accomplish the Christian tradition and try to keep what is written in the Holy Bible?
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Once the Roman Emperor; Constantine the Great; made that Christianity began the transition as the dominant religion of the Roman Empire:

So after legalizing Christianity Constantine called the leaders of Christianity to him at Nicea a suburb of Constantine's capital Constantinople.

First Council of Nicea
Constantine had invited all 1,800 bishops of the Christian church within the Roman Empire (about 1,000 in the east and 800 in the west), but a smaller and unknown number attended. Eusebius of Caesarea counted more than 250,[19] Athanasius of Alexandria counted 318,[10] and Eustathius of Antioch estimated "about 270"[20] (all three were present at the council). Later, Socrates Scholasticus recorded more than 300,

At this Church Council Constantine wanted a unifying definition of what it was to be Christian... The Nicean Creed (325 AD).

After Constantine got the unifying creed, Christianity fell into strife for the next several hundred years as Christianity struggled to adhere to a single collective belief system. The heresies encountered fell into three catagories, Trinitarian/Christological; Gnostic; and other heresies.

Early Christianity(Heresies)

• Gnosticism – 2nd to 4th centuries – reliance on revealed knowledge from an unknowable God, a distinct divinity from the Demiurge who created and oversees the material world.
• Marcionism – 2nd century – the God of Jesus was a different God from the God of the Old Testament.
• Montanism – 2nd century – relied on prophetic revelations from the Holy Spirit.
• Adoptionism – 2nd century – Jesus was not born the Son of God, but was adopted at his baptism, resurrection or ascension.
• Docetism – 2nd to 3rd century – Jesus was pure spirit and his physical form an illusion.
• Sabellianism – 3rd century – the Father, Son, and Holy Spirit are three modes of the one God and not the three separate persons of the Trinity.
• Arianism – 3rd to 4th century – Jesus, as the Son, was subordinate to God the Father.

The most powerful of the early Christian Heresies was Arianism, which actually took over the church for several decades as Constantine himself and several of his successor Emperors came to support this interpretation of Christian doctrine.

Not until the co-reigns of Gratian and Theodosius 378 AD was Arianism finally dealt with.

List of heresies in the Catholic Church Arianism - Denial of the true divinity of Jesus Christ taking various specific forms, but all agreed that Jesus Christ was created by the Father, that he had a beginning in time, and that the title "Son of God" was a courtesy one..

From: LаngLаngС
since there was not the Christian tradition early on (brand new has by definition no tradition, then there were countless Christianities…) and "keep what is written" needs qualification: canonised (again the?)

The vast majority of all "Christians" today subscribe to the Nicean Creed so with a Question which both references "Christian tradition" and the Contantine I think it's more than reasonable to begin with The first ecumenical (representing a number of different Christian churches) council at Nicea, and the Heretical troubles which entailed after.

From: LаngLаngС
bible is later than most traditions, unclear what counts (Cath bible is different than Prot eg) and what it even means (ask Marcion, Nicolas, Luther…). Some basics may be universal, details were/are not. [Nicea is significant, but strife was always there, Marcion the first real explosion…]

Christian tradition prior to Nicea could vary by city. Each Bishop wrote his own doctrine as communication between different cities were sparse for fear of Roman persecution. Nicea was the first ecumenical church council. The first meeting where the leaders of all those who called themselves Christian were invited to meet and define a common set of beliefs. In that it is part of most Protestant traditions today (post reformation) who still say the Nicean Creed every Sunday in mass as do Catholics, and Orthodox Christians post schism. (although not universally subscribed to, those who do not subscribe to the Nicean Creed and still identify as Christian are the exception not the rule.)

Again the original question defines the beginning of the period he's interested in by referencing Constantine and the legalization of Christianity. Not Baptists 1600's.