None of that matters nor has any bearing on the question. The truth is there is only ONE God, there is NONE like Him and He gives His glory to NO ONE. If and when you come to believe this THEN the answer becomes easy. Do you believe the words of Isaiah who said these three things?
God can't reduplicate, copy, give, share His glory (of which Sinlessness, Holiness, Righteousness, etc., are His glory) to anyone. There is only ONE God. It's not God's Law by which we will be judged against. It is Him. He is the standard by which everything and everyone is judged against. There are only two people that can stad before a Holy and Sinless God and that is the Holy Son and Holy Spirit. Everything and everyone else fall short of His glory.
If sinlessness is the Nature and glory of God and if it were possible He gave, shared, copied, reduplicated this glory in Adam then by necessity Adam would have to possess ALL the Deific Attributes of God or he would fall short of God's perfect standard of glory: Himself.
I agree that is what the prophet Isaiah testified of but Isaiah also prophesied that the God that has been speaking to us since Adam and Abraham, is the same God that shall come as our Redeemer as sent by the Lord God ( The Father ) and His Spirit.
Isaiah 48:16 Come ye near unto me, hear ye this; I have not spoken in secret from the beginning;
from the time that it was, there am I: and now the Lord God, and his Spirit, hath sent me. 17 Thus saith the Lord, thy Redeemer, the Holy One of Israel; I am the Lord thy God which teacheth thee to profit, which leadeth thee by the way that thou shouldest go.
This prophesy was fulfilled at the water baptism of Jesus Christ's.
Matthew 3:15 And Jesus answering said unto him, Suffer it to be so now: for thus it becometh us to fulfil all righteousness. Then he suffered him. 16 And Jesus, when he was baptized, went up straightway out of the water: and, lo, the heavens were opened unto him, and he saw the Spirit of God descending like a dove, and lighting upon him: 17 And lo a voice from heaven, saying, This is my beloved Son, in whom I am well pleased.
For God to command men to have two or three witnesses to establish a testimony and that no single witness can condemn a man to death, per Deuteronomy 17:6 & 19:15, then how can that One God judge or testify from Himself without being a hypocrite? By how there are three witnesses within the One God.
There is no idolatry being committed here when man was created after His likeness and His image. Indeed, the request was made in the plural sense for making man in our image and after our likeness and that was the Word of God asking the father for that permission and so by the Father's will & the Spirit's compliance, the Son made man in His image and His likeness as that One God.
As you say that God will not share His glory with another and that there is none beside Him and yet Jesus testified to that at His trail for why He was crucified for blasphemy.
Matthew 26:63 But Jesus held his peace, And the high priest answered and said unto him, I adjure thee by the living God, that thou tell us whether thou be the Christ, the Son of God. 64 Jesus saith unto him, Thou hast said: nevertheless I say unto you, Hereafter shall ye see the Son of man sitting on the right hand of power, and coming in the clouds of heaven. 65 Then the high priest rent his clothes, saying, He hath spoken blasphemy; what further need have we of witnesses? behold, now ye have heard his blasphemy. 66 What think ye? They answered and said, He is guilty of death.
Here is another prophesy from Isaiah.
Isaiah 7:14 Therefore the Lord himself shall give you a sign; Behold, a virgin shall conceive, and bear a son, and shall call his name Immanuel.
Isaiah 9:6 For unto us a child is born, unto us a son is given: and the government shall be upon his shoulder: and his name shall be called Wonderful, Counsellor, The mighty God, The everlasting Father, The Prince of Peace.
John 8:23 And he said unto them, Ye are from beneath; I am from above: ye are of this world; I am not of this world. 24 I said therefore unto you, that ye shall die in your sins: for if ye believe not that I am he, ye shall die in your sins.
56 Your father Abraham rejoiced to see my day: and he saw it, and was glad. 57 Then said the Jews unto him, Thou art not yet fifty years old, and hast thou seen Abraham? 58 Jesus said unto them, Verily, verily, I say unto you, Before Abraham was, I am. 59 Then took they up stones to cast at him: but Jesus hid himself, and went out of the temple, going through the midst of them, and so passed by.
Jesus is the God of Abraham, Isaac, & Jacob that mean had seen in the O.T. and even Moses had seen him and written of Him.
John 5:39 Search the scriptures; for in them ye think ye have eternal life: and they are they which testify of me. 40 And ye will not come to me, that ye might have life....
46 For had ye believed Moses, ye would have believed me; for he wrote of me. 47 But if ye believe not his writings, how shall ye believe my words?
Jesus said plenty of times that He is God.
John 10:28 And I give unto them eternal life; and they shall never perish, neither shall any man pluck them out of my hand. 29 My Father, which gave them me, is greater than all; and no man is able to pluck them out of my Father's hand. 30 I and my Father are one. 31 Then the Jews took up stones again to stone him. 32 Jesus answered them, Many good works have I shewed you from my Father; for which of those works do ye stone me? 33 The Jews answered him, saying, For a good work we stone thee not; but for blasphemy; and because that thou, being a man, makest thyself God.
The question is, do you continue to gloss over these scripture to keep with what you have been taught or do you desire truth in Jesus Christ?