So, to boil down your extremely long thought, I assume you are saying that this doctrine is hidden in an obvious way in the book of Genesis. In other words, one can extrapolate this doctrine from much of Genesis.
I do not see it there, although I see how you got there. I just don't see a correlation between animal sacrifice to cover sins, and freely giving of your own life for that of others.
Jesus does say this is a "new" commandment. Who is it new for? Jesus is directing this to the disciples. Why would this be new for them after His 3 years of teaching? He doesn't quote from the OT to explain it. I think we need to take Jesus at His word that this is a new commandment.
I don't think there is anything wrong with Jesus instituting a new commandment, especially since these are the first Christians and this command is for Christians.
Another new doctrine Jesus taught was that God's only begotten son would be the vehicle to redeem man and pay his debt.
This again, you can find hints to in the book of Isaiah and Psalms, but it was never taught by any of the prophets.
A long thought is better than a short one .
Though oen can think it over a long period of time or in one go .
I do not understand your last conclusion in your last two sentences.
One the foundational thought that jesus Himself reproved the two disciples on the road to Emaus
"oh fools and slow of heart to believe all that the prophets have spoken: ought not Christ not to have suffered these things and to enter into his glory"? Luke 24:25-26
27 "and BEGINNING at Moses and all the prophets he expounded unto them in ALL the scriptures the things concerning himself "
It is therefor taught but as the scriptures say of it "In sundry times and in divers ways "
The fall of man did not catch God unawares or unexpectedly ,The Salvation of God who is Jesus Christ was preordained from before the foundations of the world .Even as it is said "As of the Lamb slain from the foundation of the world" Rev 13 :8
The lamb slain by Abel was but a foreshadow of Him who was to come and was promised by God in the garden and which is why his offerring was accepted and Caines was not.
For Cain rejected the blood of the lamb and thus found no place of repentance.
Moses wrote by inspiration of God the book of Genesis as also the first 5 books ,
Jesus " Beginning at Moses......................."
and who else fits the description of a single ("IT") male ("HE") child born of a woman ,but not of Adams seed ? Who would destroy the works of the devil? Who in bruising the head of the serpent would sufffer in doing so by being bruised in his heel?
With hindsight which is not denied it clearly speaks of the Lord Himself . Who would come as "the Lamb that woudl take away the sin of the world."
and what of the lamb sacraficed in Egypt and the blood shed on the doorposts and lintels?
What of the substitute sacrafice given by God instead of Issac?
This OP is called the hope of his calling . Even by the argument of the poster and others ,Did not Abraham die in that hope? as did others as listed in Hebrews by Paul?
The New testament has depths ,breadths and hights to it that we cannot know unless it is seen in the light of the Old testement .
and if we do but read the Old we are left unfinished or as pauls says "were not made perfect withiut us"
In truth how can we know Him "who is from the beginning" if we do not learn to swim in its waters ?
in Christ
gerald