Unitarianism is simply the flipside of the same erroneous coin that Trinitarianism is on. They both teach, incorrectly, a singularity. The truth of the matter is, there are Three Eternal Persons/Beings, that work together, as a "Trio" in scripture.
Would you be willing to discuss, scripturally, your points above?
You stated:
Correct, by scripture:
Heb 1:1 God, who at sundry times and in divers manners spake in time past unto the fathers by the prophets,
Heb 1:2 Hath in these last days spoken unto us by his Son, whom he hath appointed heir of all things, by whom also he made the worlds;
Heb 1:3 Who being the brightness of his glory, and the express image of his person, and upholding all things by the word of his power, when he had by himself purged our sins, sat down on the right hand of the Majesty on high;
You stated:
Incorrect. Here is where you erred at the outset. The Son of the Father, is as eternal as the Father is, by scripture itself:
Joh 1:1 In the beginning was the Word, and the Word was with God, and the Word was God.
Joh 1:2 The same was in the beginning with God.
Joh 1:3 All things were made by him; and without him was not any thing made that was made.
Pro 8:30 Then I was by him, as one brought up with him: and I was daily his delight, rejoicing always before him;
Col 1:15 Who is the image of the invisible God, the firstborn of every creature:
Col 1:16 For by him were all things created, that are in heaven, and that are in earth, visible and invisible, whether they be thrones, or dominions, or principalities, or powers: all things were created by him, and for him:
Col 1:17 And he is before all things, and by him all things consist.
1Jn 1:1 That which was from the beginning, which we have heard, which we have seen with our eyes, which we have looked upon, and our hands have handled, of the Word of life;
1Jn 1:2 (For the life was manifested, and we have seen it, and bear witness, and shew unto you that eternal life, which was with the Father, and was manifested unto us;)
1Jn 1:3 That which we have seen and heard declare we unto you, that ye also may have fellowship with us: and truly our fellowship is with the Father, and with his Son Jesus Christ.
The Son already existed before
all created things "with" the Father. There was never a time of existence in which the Father exists, that the Son did not also exist with the Father. The Throne of God has eternally had two places, The place for the Father, and at His right hand the place for the Son. The Third Person of the Godhead (Holy Ghost/Spirit), may also be discussed, as He is more mysterious than the other two in the sense of Personality (Personhood), as His nature is not told us in scripture, but is not in focus in this present response to this point.
In fact, the Father, could not have been eternally "the Father", if the Son had not eternally existed alongside "with" the Father. The "Father" would then have 'become' a Father, which is a change of character, which the Bible does not teach.
There is no place in scripture, in which the Son is 'created'. The human flesh body (Hebrews 10:5; Psalms 40:6) is 'created' for Him (the Son) at a later period, but not the Person of the Son Himself. Philippians, and the other texts noted, are clear:
Php 2:5 Let this mind be in you, which was also in Christ Jesus:
Php 2:6 Who, being in the form of God, thought it not robbery to be equal with God:
Php 2:7 But made himself of no reputation, and took upon him the form of a servant, and was made in the likeness of men:
Php 2:8 And being found in fashion as a man, he humbled himself, and became obedient unto death, even the death of the cross.
Php 2:9 Wherefore God also hath highly exalted him, and given him a name which is above every name:
Joh 8:58 Jesus said unto them, Verily, verily, I say unto you, Before Abraham was, I am.
The Son can only witness of the Eternal Nature and Character of the Father, if He was present at all such existence/time "with" the Father, otherwise, He would be merely guessing. He could not even have demonstrated that name on earth, unless He experienced that in/from eternity "with" the Father.
