Tertullian's teachings!!
Trinity!! In his treatise against Praxeas, who taught patripassianism in Rome, he used the words "trinity", "economy"
(used in reference to the three persons), "persons", and "substance," maintaining the distinction of the Son from the
Father as the unoriginate God, and the Spirit from both the Father and the Son "These three are one substance, not
one person; and it is said, 'I and my Father are one' in respect not of the singularity of number but the unity of
the substance."
The very names "Father" and "Son" indicate the distinction of personality. The Father is one, the
Son is another, and the Spirit is another and yet in defending the unity of God,
he says the Son is not other as a result of receiving a portion of the Father's
substance.
[13] At times, speaking of the Father and the Son, Tertullian refers to
"two gods".[13][d] He says that all things of the Father belong also to the Son,
including his names, such as Almighty God, Most High, Lord of Hosts, or King of
Israel.