Questions on biblical texts relating to the Christian teaching of the "Trinity", that one God exists in three "persons": Father, Son, and Spirit.
Although the Christian Bible nowhere uses the term "Trinity", orthodox Christians believe that one God exists in three "persons": God the Father, God the Son, and God the Holy Spirit. As the Athanasian Creed puts it:
And the catholic faith is this: That we worship one God in Trinity, and Trinity in Unity; Neither confounding the Persons; nor dividing the Essence. For there is one Person of the Father; another of the Son; and another of the Holy Ghost. But the Godhead of the Father, of the Son, and of the Holy Ghost, is all one; the Glory equal, the Majesty coeternal. ...
This is further elaborated in the Creed. Its date is unknown -- probably dating around the 5th-6th Century -- but it is widely regarded as the earliest explicit pronouncement on the Three-in-Oneness of the Christian God.
Questions on Hermeneutics.SE relating to the Trinity should focus on a particular biblical text or set of texts which contribute to an understanding of the Trinity. This is not the place for questions discussing or exploring the doctrine of the Trinity itself; these might find a home on Christianity.SE.
Some trinity questions with > +6 votes currently on the site include: