Trinity

a word not found in Scripture, but used to express the doctrine
of the unity of God as subsisting in three distinct Persons.
This word is derived from the Gr. trias, first used by
Theophilus (A.D. 168-183), or from the Lat. trinitas, first used
by Tertullian (A.D. 220), to express this doctrine. The
propositions involved in the doctrine are these: 1. That God is
one, and that there is but one God (Deut. 6:4; 1 Kings 8:60;
Isa. 44:6; Mark 12:29, 32; John 10:30). 2. That the Father is a
distinct divine Person (hypostasis, subsistentia, persona,
suppositum intellectuale), distinct from the Son and the Holy
Spirit. 3. That Jesus Christ was truly God, and yet was a Person
distinct from the Father and the Holy Spirit. 4. That the Holy
Spirit is also a distinct divine Person.