Many Christians of the present times believe that God is a Trinity and many would agree that the Trinity Doctrine is a major doctrine of Christianity that laid the basis for the Christian belief. A stronger test of the early church was that of the heretical Arians (Jehovah's Witnesses today), and heresy was this that motivated the early church to formalize the doctrine of the Trinity (Antognazza, 2001, p. 1-13). The modern Arians or Jehovah's Witnesses, we could say that they are polytheists, because according to the New World version of the Bible in John 1:1 reads as follows:
"In [the] beginning the Word was, and the Word was with God and the Word was a god."
Development of the Doctrine of the Trinity
The doctrine of the Trinity was developed in close association with the New Testament evidence of the divinity of Christ (e.g. Phil. 2:6, Hebrews. 1:1-10). Historically, it has developed in the West before the East. Theological doctrine of completeness, this was in the works "Cappadocia Fathers" in the period between the first and second ecumenical councils. Brothers, Basil the Great and Gregory of Nyssa, but above all, their friend, Gregory Nazianzen, launched a decisive explanation for the internal connection between a single entity (substance), and three persons (hypostases) of God. The distinction between the Persons of the Trinity was conducted as follows: Father - unborn Person, the Son - born eternally Person, the Holy Spirit - coming from the Father of Personality (Waller, 2009, p. 145-146).
Despite this functional division, all the Persons of the Trinity have one nature. In the year 215 AD, Tertullian was the first to establish this doctrine using the term, Trinidad. Some of the false doctrines that arose at that time such as Gnosticism (Christian Science ...