You write that I ‘do not understand the belief of Trinitarians.’
Unless you are over the age of seventy, I became a Trinitarian before you were born.
Concerning the Doctrine of the Trinity:
The Fourth Lateran Council (1215 C.E) declared:
‘We firmly believe and simply confess that there is only one true God, eternal and immeasurable, almighty, unchangeable, incomprehensible and ineffable, Father, Son and Holy Spirit, three persons but one absolutely simple essence, substance or nature.’ (Constitutions: 1. Confession of faith).
The Council of Basel (1431-45 C.E.) decreed:
‘First, then, the holy Roman church, founded on the words of our Lord and Saviour, firmly believes, professes and preaches one true God, almighty, immutable and eternal, Father, Son and Holy Spirit; one in essence, three in persons……………… These three persons are one God not three gods, because there is one substance of the three, one essence, one nature, one Godhead, one immensity, one eternity……. Therefore it condemns, reproves, anathematizes and declares to be outside the body of Christ, which is the church, whoever holds opposing or contrary views. Hence it condemns Sabellius, who confused the persons and altogether removed their real distinction. It condemns the Arians, the Eunomians and the Macedonians who say that only the Father is true God and place the Son and the holy Spirit in the order of creatures. It also condemns any others who make degrees or inequalities in the Trinity.’ (Session 114).
Tertullian, the third-century church father writes:
‘Father and Son and Spirit are three, however, not in status but in rank, not in substance but in form, not in power but in appearance; they are, however, of one substance and of one status and of one power, because God is one, from whom these ranks and forms and appearances are designated in name as Father and Son and Holy Spirit.’ (Adversus Praxean; Chapter 2).
Trinitarians believe that within the Godhead (the ‘one Substance’) the Father is entirely within the Son and entirely within the Holy Spirit. The Son is entirely within the Father and entirely within the Holy Spirit. The Holy Spirit is entirely within the Father and entirely within the Son. In other words, the three Persons form a single unity, indivisible and permanent. They are not three persons standing side by side, so to speak.
As you can see from the above, the Church teaches that God is ‘immutable’.
By ‘immutable’ is meant that in God there can be no change whatsoever.
The Dominican theologian, St Thomas Aquinas bases the absolute immutability of God on His absolute simplicity (a Spirit, having no parts); on His pure actuality (He has no potential for change); and on His infinite perfection.
According to Aquinas, mutability includes potentiality, composition and imperfection and as such is irreconcilable with God as ‘actus purus’ (the absolutely simple, absolutely perfect Essence). (cf. Summa Theologica: Part 1; Question 9; Article 1).
The 4th Lateran Council and the First Vatican Council taught that man consists of two essential parts – a material body and a spiritual soul (Denzinger 428, 1783).
Fourth Eucharistic Prayer (part of the Catholic liturgy) states (my emphasis):
‘And you so loved the world, Father most holy, that in the fullness of time you sent your Only Begotten Son to be our Savior. Made incarnate by the Holy Spirit and born of the Virgin Mary, he shared our human nature in all things but sin.’
Humans have but one nature (I know of no Christian doctrine that teaches otherwise).
If Christ has two natures (one human and one divine) then he cannot possibly be like us in ‘all things but sin.’
If, on the other hand, he truly is like us in all things (but sin) then he cannot possibly be God.
Trinitarians simply cannot have it both ways.
There is broad agreement among New Testament scholars (and has been for decades) that Yeshua did not consider himself to be God.
Consider, by way of example, the following quotations (from Trinitarians):
‘Any case for a “high” Christology that depended on the authenticity of the alleged claims of Jesus about himself, especially in the Fourth Gospel, would indeed be precarious.’ (The Rev. C.F.D Moule: ‘The Origin of Christology’).
‘Jesus did not claim deity for himself’ (Archbishop Michael Ramsey: ‘Jesus and the Living Past’).
‘There is good evidence to suggest that (Jesus) never saw himself as a suitable object of worship’ and that it is impossible to base any claim for Christ’s divinity on his consciousness once we abandon the traditional portrait as reflected in a literal understanding of St. John’s Gospel’ (The Rev. David Brown: ‘The Divine Trinity’)
‘It is no longer possible to defend the divinity of Jesus by reference to the claims of Jesus’ (Canon Brian Hebblethwaite: ‘The Incarnation’).
Here is a quote by Cliff Reed, a Unitarian minister:
‘Unitarians believe that Jesus was a man, unequivocally human. It has long been our view that to talk of him as God is unfaithful to his own understanding of himself. The New Testament accounts describe a Jewish man, chosen, raised up, adopted and anointed by God. They claim that the divine purpose was that Jesus should reconcile first the Jews and then all humanity to each other and to God. This would prepare the way for the Messianic age of peace.’ (Sourced from a Unitarian website).
I agree with Cliff Reed.