It is 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 Greek Trias, first used by Theophilus (AD 168-183) or from the Latin Trinitas, first used by Tertullian (AD 220), to express the doctrine.
The prepositions involved in the doctrine are these:
- That God is One, and that there is but one God (Deut 6:4)
- That the Father is a distinct divine Person, distinct from the Son and the Holy Spirit.
- That Jesus Christ was truly God, and yet was a Person distinct from the Father and the Holy Spirit.
- That the Holy Spirit is also a distinct divine Person.