If we ask a trinitarian "What is the trinity?", we might not receive the same answer from each individual who professes belief in the trinity. According to the CARM site, the trinity is defined as meaning "God is three persons;" "Each person is divine;" and "There is only one God." One of the WIKI articles favorable to the trinity doctrine claims:
The Trinity is a Christian doctrine, stating that God is one being who exists, simultaneously and eternally, as a mutual indwelling of three persons: the Father, the Son (incarnate as Jesus Christ), and the Holy Spirit. Since the beginning of the third century the doctrine of the Trinity has been stated as "that the one God exists in three Persons and one substance, Father, Son, and Holy Spirit". Trinitarianism, belief in the Trinity, is a mark of Oriental and Eastern Orthodoxy, Roman Catholicism and all the mainstream traditions arising from the Protestant Reformation, such as Anglicanism, Lutheranism and Presbyterianism; and the Trinity has been described as "the central dogma of Christian theology".
From this, however, the trinitarian has to give the terminology used unique meanings as applied to the trinitarian dogma.
It is claimed that although the word "trinity" does not appear in the Bible, that the concept of the trinity does appear there. And yet, in all of the array of scriptures that the trinitarian presents to allegedly support that concept, the concept of the trinity -- three persons in one God -- has to be added to and read into each and all the scriptures presented to allegedly support that concept. The concept of the trinity itself is no where presented in the Bible, without the scriptures being filtered by the tint of the trinitarian dogma being laid over the scriptures in order that the concept be given the appearance as being in the scriptures presented. This will become apparent as the scriptures are examined.
Some trinitarians may admit that the scriptures do not directly state that there are three persons in one God, but that by taking all of the scriptures together, one is justified in adding that concept to the scriptures. Some may claim that one has read the scriptures in the tint of the trinitarian dogma, or else the scriptures are contradictory. Again, in reality, the scriptures can be seen to be in perfect harmony without adding to the scriptures a story of three persons in one God.
Many, however, do not realize that in detail, there are varying opinions concerning the trinity amongst the leaders to who teach that doctrine. One of the most known differences is that some believe in the "functional subordination" of their "God the Son" to God the Father; others do not believe in that subordination. (This, Yahweh willing, will be dealt with later, as a separate topic.) Additionally, there is a dispute amongst trinitarians regarding practically every scripture that is presented to support that doctrine. Usually, however, those trinitarian scholars who may claim that a certain scripture cannot be used to support the dogma are ignored by the larger body of trinitarian scholars. For instance, some trinitarians see "trinity" in the Hebrew words ELOHIM and ECHAD, while others do not.
For more regarding the Biblical meaning of ELOHIM, see:
Elohim – Does This Word Indicate a Plurality of Persons in a Godhead?
For more regarding the Biblical meaning of ECHAD, see:
The Meaning of ECHAD
We might add that the vast spectrum of Christians of all denominations, when asked what they believe the trinity is, may give an answer something like: "belief in the Father, the Son and the Holy Spirit." These do not usually think in the theological terms in defining "trinity" as "three persons in God," etc. Indeed, all Christians should believe in "the Father, the Son and Holy Spirit", whether they believe in the trinity dogma or not, and if "trinity" should be stated in such terms, without adding all of the other trinitarian philosophy, we too can say that we believe in such a trinity, that is, we believe in "the Father, the Son and the Holy Spirit."