From a non-Trinitarian perspective, how would you show that the Bible does not teach that the Son is equal with the Father?

"the Bible does not explain the relationship between the Father and Son in terms of substance or being"

Really? All the Gospels and all the Epistles show Jesus to be God's holy, human son who was mortal in the flesh - made like us in every respect, born of Mary,

Gal 4:4 But when the fullness of the time came, God sent His son, born of a woman, born under the Law.

who has a God, and now ascended and exalted, appointed heir by God, still has a God who he sits next to and has been given life by God twice. He had no power within himself but did all his works by God in him through the power of the spirit - words included. He is always subordinate to God and still is, God granting him authority while on earth and now in heaven to have all things under him - except God.

God IS spirit, Jesus said he was not a spirit. That's a plain statement about substance.

What of all that small sample doesn't express relationship?

And a voice from heaven said, “This is my Son, whom I love; with him I am well pleased. Matt 3:17

Why was God pleased? Because Jesus expressed his love by trusting and obeying God - just as we are called to.

Does the Bible present Jesus as eternally equal with the Father?

No. Absolutely, positively no. The onus is on contrary views to prove otherwise, which they must do by reading-in various doctrines of men to the scriptures which the early church and Apostles never taught or believed. The list of verses that are mis-read and taken out of context to promote an 'eternal and equal Jesus’ are all readily shown to be an interpretation based on ideas of men formed 100's of years after the Apostles.

So, I am particularly interested in indications that the Son was equal or subordinate to the Father before He “became flesh” and after His ascension.

Jesus has no biblical evidence of him pre-existing his birth. Prophecy points to the one to come, from before the foundation of the world. We can only read-in an other understanding.

The oft quoted John 1:1-3 is shown by 1John 1 to not be referring to a ‘person’ but the inanimate word, message, statement of God. That “which” through God delivered His will for things to be so. The ‘word’ has life because God uttered it and Jesus was conceived!

In all matters, we must simply read the facts as presented and not infer or make our own assumptions - let the bible interpret the bible with the readily understood scripture used to inform the difficult ones.

The Trinity doctrine is inconsistent with the Bible

If we take the matters mentioned and try to align them with said doctrine, we have to read in so much to even begin to approach the plain simple and consistently expressed truths from the inspired writers of the NT, let alone readily agree with! The following biblical truths are not compatible with a trinity doctrine.

Can the Bible answer this question?

Absolutely - without adding anything or taking the words out of contect. The bible teaches Jesus is a man and so cannot be equal to God, never mind be God.

• that's why he can be tempted - in all things Heb 4:15 (God cannot be tempted James 1:13)

• that's why he can die - God sent His only son... John 3:16, God is immortal 1 Tim 6:16 (a two-natured Jesus is unbiblical, as is a God the Son - never mentioned anywhere in scripture)

• that's why he inherited everything - which is odd if he allegedly made everything Heb 1:2

• that's why Jesus tells us he is a man - John 8:40 'a man who has spoken the truth that I heard from God' (in his own words) Rom 5:15, Acts 2:22, Acts 17:31, 1 Tim 2:5 (one God and one mediator ... the man Christ Jesus)

• that's why he was foreknown by God 1 Pet 1:20 and prophesied because he was to come.

• that's why he is the last Adam (which makes him only human) 1 Cor 15:45

• that's why he had and has a God - the same God as everyone else Rom 15:6, John 20:17 The God he now sits next to! Heb 12:2, Col 3:1

• that's why the NT tells us repeatedly that Jesus is not = to the Father - in anything. His Father is the one granting everything that Jesus has, including life! John 5:26

• that's why he had to grow in wisdom learning obedience through suffering Luke 2:52, Heb 5:8

• that's why he could do nothing of himself - even his words were the Father's John 5:19

• that's why he was mastered by death Rom 6:9 because if he sinned he would lose the promise of eternal life Heb 5:7. Jesus is not immortal until he is raised.

Jesus can be the new god of this world - replacing the present god of this world by a fair fight and a glorious victory. Did Satan really try to tempt God or defeat God by deception and prideful reasoning? Either Jesus IS God, or he is not - we cannot have it both ways! Using Phil 2 to say he emptied himself of his divinity is an absurd concept not intended by the text, yet is a centrality of the two-natured Jesus being a man, while still somehow being God.

Yes, the trinity is inconsistent with plain bible revelation when taken in context and the additions and biased translations are recognised. Adding a new verse (1John 5:7) and adding other words to force a trinitarian view is not only dishonest, but effectively playing God with the inspired text.

The Word, which was in the beginning with God and which was God, is what was made into flesh and dwelt among us as the man Jesus (John 1:1, 14).

It is abundantly clear that this man, Jesus, was subordinate to God the Father while in the flesh for He completed all the work the Father gave him to do (John 17:4), spoke what he was given to speak (John 8:42).

It is also abundantly clear that in this current age, in which Jesus has been resurrected to the right hand of power (Heb 1:3), that He has been given the name that is above every name (Phil 2:9) and that when he (Jesus) is confessed as Lord it is to the glory of God the Father (Phil 2:11).

This term Lord has to do with authority and power so when things in heaven, on earth, and under the earth confess Jesus as their authority and power (Lord) this glorifies God the Father. It is also not explicitly clear that God the Father is included in those who must kneel and confess.

Indeed, it is made clear that the one who puts all things under his (Jesus') feet is excepted from that subjection (1 Cor 15:27) and that it is Jesus who will, at the presentation of the Kingdom to God, subject himself also so that God may be all in all (1 Cor 15:28).

It is interesting to note that all of these terms of humility, obedience, and subjection appear in connection with the created order of things. Even before the Word was made flesh and dwelt among us that Word was performing the will of God by creation and within creation:

So shall my word be that goeth forth out of my mouth: it shall not return unto me void, but it shall accomplish that which I please, and it shall prosper in the thing whereto I sent it. - Isaiah 55:11

It is also interesting to note that prior to the creation of anything the Word was God and, following the resolution of creation when the Word (Jesus) presents both himself and the subdued creation in subjection that God is then (once again) all in all.

Since this word Logos (Word) includes not just the act of speech but also the rationality behind the speech; not just the divine Word but the divine Mind behind that Word, we are left asking:

1. Prior to any act of creation, when the Word (mind and speech) was God, is it sensible to ask if God's Mind is in subjection to God's nature or is it more sensible to state that God's Mind is part of God's nature?

2. Following the resolution of creation, when the Word returns unto God (not void, but having accomplished everything for which it was sent) and God is (again) all in all, is it sensible to ask if the subjection under which the Word was sent continues or is it more sensible to state that, all things having been accomplished, the subjection is now also ended?

If the Word (Mind of God) is a part of God's nature and if Divine Simplicity be true (that understanding that God is not made of fractional parts but is 100% of every attribute) then the Word is not ontologically in subjection either before creation or after. What is in between (during creation) is something that appears more voluntary than ontological:

Then said I, Lo, I come (in the volume of the book it is written of me,) to do thy will, O God. - Hebrews 10:7

For I came down from heaven, not to do mine own will, but the will of him that sent me. - John 6:38

Therefore the Word is not unequal to God in being, may be in subjection voluntarily, and that subjection need not and does not erase the underlying equality.

"From a non-Trinitarian perspective, how would you show that the Bible does not teach that the Son is equal with the Father?"

It's hard to believe that with all of the lengthy responses provided so far, the clearest answer to this question has been entirely neglected. And it is simple.

Jesus said:

Ye have heard how I said unto you, I go away, and come again unto you. If ye loved me, ye would rejoice, because I said, I go unto the Father: for my Father is greater than I. (John 14:28, KJV)

That should be definitive.

Whether you realize it or not, you are basically asking (at least) two completely different questions rolled up into one; and, not only that, but (at least) one of these contains, in its turn, (at least) two different sub-questions.

if the Son, in “eternity” is subordinate in His “role/function,” then He is also subordinate in His “being:”

eternal role subordination by necessity implies subordination in person or being.

eternal subordination in being/nature/essence and work/operation/function are two sides of one coin.

This is pretty much the Arian argument, namely that subordination in hypo-stasis (person or sub-stance) automatically implies subordination in ousia (essence). Needless to say, the fathers of both Nicaea and Constantinople vehemently disagreed with their perspective, as did the Cappadocians.

Two Views among Evangelicals

• the Son is eternally subordinated to the Father.
  the eternal subordination of the Son
• Bible writers present the Son as equal with the Father

While the above statement(s) might indeed be reckoned as two views by Evangelicals, they were regarded as one view among the aforementioned ecumenical fathers, who gave us the Nicene creed.

this distinction ”is entirely novel. It has no historical antecedents.

...in the Christian West, of which Evangelicals are certainly part of, both culturally and intellectually. But the ecumenical councils, along with all the heresies, disputes, and controversies they were convened to settle, took place in the East and Orient. This is an important distinction to be made.

[in] the Athanasian Creed, it states:

The Bible teaches that the Father is God, that Jesus is God, and that the Holy Spirit is God. The Bible also teaches that there is only one God.

The Athanasian creed, unlike Athanasius himself, is a Western creed: notice its use of the filioque, for instance. What is the rationale behind this distinctly Western teaching ? That, since the Father and the Son share one and the same divine nature, and since spiration is an attribute of the Father, then it must of necessity follow that the Spirit proceeds from the Son as well.

But this blurs the (fine) line or distinction between hypostatical attributes, specific to each divine person, in particular; and natural characteristics, common to all three divine persons, in general; a clarifying distinction, championed by the Cappadocians, which greatly helped ease the widespread acceptance of the two imperial councils of Nicaea and Constantinople.

Similarly here, with Evangelical scholars not discerning between ontological and personal subordination, be it temporal or eternal, since it's never actually formed an integral part of the Western worldview or perspective, various theological similarities between Eastern Orthodoxy and Roman Catholicism, from which Protestantism historically emerged, notwithstanding.

Basically, what this question is actually asking, whether the OP is aware of it or not, is if there is a way to determine which philosophical system is best fitted for interpreting or understanding scripture:

• the Western one, espoused by Augustine or Aquinas, and ultimately inherited by (Evangelical) Protestantism from Roman Catholicism;

• the Eastern one, espoused by the (mostly eastern) fathers of the (first two) ecumenical councils.

If there were indeed a purely-biblical answer to this question, then the East-West schism would probably either never have happened, or, alternately, the two sides would not have been so evenly split at the time of its occurrence.

this is not a question that will interest Catholic Christians, since they rely on tradition

Nonsense ! It interests me, an Eastern Orthodox, whose religious tradition is very similar to theirs; why would it not interest them as well !?

Now that the question has been changed, I can give an answer. I am staunchly Trinitarian, but I am very familiar with literature that is non-Trinitarian, and which argues for the subordination of the Son to the Father (before becoming man, and after returning to heaven). I can offer an answer from such literature. The only trouble is, collating every single proof-text with attached interpretations/explanations would require a huge amount of time and take up dozens of pages of text.

Therefore, I just propose to give a summary review of the main arguments used.

First, it is maintained that the Son was created by the Father at a certain point in time. That instantly caused a two-tier level between them. The Father was never created but is God from eternity, then he created this Son as his first act of creation. A creature is never to be worshipped, so a created Son cannot receive worship which is due only to God the Father, and that is the main proof of subordination, they say.

If this first point is non-biblical, the rest of the points are questionable, but with no comment on that, here are the subsequent points.

Second, God sent the Son to Earth as a human, born of the virgin Mary, and loads of proof-texts are used to claim subordination while he was on Earth. Of course, Trinitarians agree that the Son had lowered himself from his heavenly state (in the Godhead, as they put it), which accounts for all those scriptures. However, as Trinitarians says Jesus was God incarnate, but non-Trinitarians disagree with that, there can be no meeting of minds there. For example, one group says the Bible shows the Son receiving and accepting worship while he was on Earth. Non-trinitarians insist that the Bible never supports that claim.

Third, when Jesus was resurrected and returned to heaven, they say he was still the greatest of God's creatures, remaining the archangel Michael. And although the King of God's Kingdom, he will relinquish that post and hand it over to the Father at the end, when everything has been restored. He is said to never receive worship, even in heaven. Again, Trinitarians insist that the Bible shows the opposite, but there is neither time nor space to do justice to examining such opposing views.

Those three points are the fundamental reasons non-Trinitarians give for saying that the Bible does not teach that the Son is equal with the Father. It is all a matter of how the many Bible verses involved are interpreted. There are hundreds of Bible verses involved, so it is impossible to deal with them all, explaining the rationale of both groups, as the question asks for, because little short of a book would need to be written to do justice to the scope of this enormous question. As books have already been published on the question, I do not intend to reinvent the wheel.

The simple answer is that the Father's relationship with the Son is exactly that. Within a family, regardless of actual capability, sons are considered subordinate to fathers, expected to honour and respect them.

The Son may be a totally independent being, the Father's equal in all other respects, but their family relationship defines a situation where one has a greater position of authority than the other. This relationship is perfect, not one of resentment or even of acceptance, but one of mutual love, one to be embraced.

Many believe that the Bible simply uses terms like "Father" and "Son" as a convenient metaphor so that human families can provide a superficial basis for our limited understanding of the divine nature.

But consider the opposite perspective: it is the human family that serves as a type of the true holy relationship.

The following is extracted from a much longer article by Dexter B. Wakefield (emphasis theirs):

… Scripture reveals that the familial nature of God is not anthropomorphic; rather, the familial nature of the family is theomorphic. The human family is modeled after God's nature. Those who prefer their human reasoning to God's revealed knowledge get it backward.

The Father is actually a father, and He is the reality of what human fatherhood pictures. Jesus Christ is actually a husband and our great, firstborn Elder Brother. The New Jerusalem is called the "mother of us all" (Galatians 4:26). Resurrected saints are actually sons of God, and the Church collectively is actually a bride, the affianced wife of Christ.
…
"Then God said, 'Let Us make man in Our image, according to Our likeness'" (Genesis 1:26). The Bible often describes God and man as having characteristics in common, but God is not like man — man is like God.
…
When God teaches us that "as many as received Him, to them He gave the right to become children of God" (John 1:12), He means true children. "For you did not receive a spirit of slavery to fall back into fear, but you have received a spirit of adoption [sonship]. When we cry, 'Abba! Father!' it is that very Spirit bearing witness with our spirit that we are children of God, and if children, then heirs, heirs of God and joint heirs with Christ — if, in fact, we suffer with him so that we may also be glorified with him" (Romans 8:15–17, NRSV). And we will also be "conformed to the image of His Son, that He might be the firstborn among many brethren" (v. 29).

Many people cannot bring themselves to believe what the Bible actually says: that we are created to be the Father's true children, sons of God, joint heirs with Christ, to be glorified with Christ, conformed to the image of Christ who is the firstborn of many sons of God. The Father is actually making children and bringing us to His glory, and Christ Himself calls us His brethren (Hebrews 2:10–11).

This is not merely a "family-like relationship" or an analogy. It is the reality of family. We are to be glorified with Christ and to be the same kind of son that He is, though clearly lesser in power and authority than He and the Father. Our Elder Brother has all power in heaven and earth, and He is going to share with us the glory that He and the Father had "before the world was" (John 17:5). This is because the Father's great transcendent purpose for mankind is the creation of immortal children (1 Corinthians 15:53–54).

Human reproduction is only a physical type of this greater spiritual reality. This is why Herbert W. Armstrong said: "God is reproducing Himself!" The Father plans to bring children into the glory and oneness that He and the firstborn Son have together. Christ said: "Holy Father, keep through Your name those whom You have given Me, that they may be one as We are" (John 17:11, cf. v. 22). It is not a question of whether God is one, but how God is one. The oneness of the human family is a physical type of the greater spiritual reality of the oneness of God.

Scripture is clear. "Behold what manner of love the Father hath bestowed upon us, that we should be called the sons of God… Beloved, now we are the sons of God; and it doth not yet appear what we shall be; but we know that, when he [Christ] shall appear, we shall be like him, for we shall see him as he is" (1 John 3:1–2, KJV).

This is our incredible human potential! Our Elder Brother "will transform our lowly body that it may be conformed to His glorious body, according to the working by which He is able even to subdue all things to Himself" (Philippians 3:21). These plain statements are so astonishing that many people simply cannot believe what God is saying. But this revealed knowledge is at the core of a full understanding of the Gospel of the Kingdom of God.
…
Stated simply, "God is family," and understanding what this means is at the heart of the Gospel of the Kingdom of God. A kingdom has a ruling family, and Christ promises: "To him who overcomes I will grant to sit with Me on My throne, as I also overcame and sat down with My Father on His throne" (Revelation 3:21). He promises to make His brethren "kings and priests to our God; and we shall reign on the earth" (Revelation 5:10), with Christ as "King of kings" (Revelation 17:14). … The Gospel of Jesus Christ is the Gospel of the Kingdom of God. This is the Gospel that He preached everywhere He went. Bringing many sons to glory in the Kingdom of God is our Father's great transcendent purpose for creating humanity, and everything revolves around this purpose! …
— God Is Creating a Family | Tomorrow's World