Proto-trinitarianism: There is one God. Jesus is God. “My Lord and my God!” (John 20:28)

Mere trinitarianism: The Father is God. The Son is God. The Spirit is God. The Father is not the Son. The Son is not the Spirit. The Spirit is not the Father.

Nicene trinitarianism: The Son was eternally begotten of the Father, and is of the same substance.

Further expressed: The Son was eternally the Word, the image of the invisible God, the Eternal Son, eternally begotten, in the bosom of the Father, the Wisdom and Power of God, the radiance of the glory of God — and all this independent of creation and before his incarnation.

With the Filioque clause: The Holy Spirit proceeds from the Father and the Son, and with them is worshipped and glorified.

Wayward (social) trinitarianism: There are three wills in God, and each is a distinct center of consciousness. The Son was not eternally begotten of the Father.