That is your presupposition. It interferes with your ability to see the plain reading of scripture.
Really,
I present a realistic presentation of the gift of life, and you present a picture of a neat little present given to one who already has life and you think that my presentation "is presupposition." That "It interferes with your ability to see the plain reading of scripture?"
How?
Does your gift present life?
Does not the Scripture state, "life is in the blood"?
Does you gift present an offering to one unresponsive and incapable of taking?
Does not the Scriptures state, "DEAD in trespasses and sin, BUT the gift of God is eternal life..."
Does you gift require one to actively participate?
Does not the Scriptures state,"NOT by the will of man."
So, perhaps you should turn your presupposition upon your own presentation of Scriptures.
For, it would seem "the plain reading of Scriptures" certainly does "interfere" with your presuppositions.