This quote regarding that one drop of Jesus’ blood would be sufficient for the human race has quite a sorted past and on reflection seems to be a source of much theological confusion between Catholics and Protestants…
The quote is from a poem about the Eucharist written by St Thomas for Pope Urban IV for the creation of the Feast of Corpus Christi.
preces-latinae.org/thesaurus/Hymni/AdoroTe.html.
cathcorn.org/hotbam/79.html
From the second link, the ancient interpretation is given:
“O loving Pelican, Jesus Lord, cleanse me, unclean, in Thy Blood, one drop of which hath power to save the whole world from all its sin.” Pie pelicane: The pelican is a symbol of Christ and of charity. There is a legend that when food fails, the pelican feeds her young with her own blood. When she is thus represented in Christian art, she is said to be “in her piety,” i.e., standing over her nest with her wings extended, and wounding her breast from which fall drops of blood. *
Please note that no where does St. Thomas say that the death of Jesus is NOT needed. He simply is remarking that the small amount of blood that we have available to us in the Eucharist is sufficient for our salvation, just like the baby birds live off small amounts of their Mother’s blood. Thus he is describing an important aspect of the doctrine of the Eucharist, namely that we receive the life of Christ himself through the Eucharist. Recall that ancients believed that blood CONTAINED life itself, your spirit, etc. That means that when we receive the blood of Christ, we receive HIS life, his spirit, even if it is a small amount of blood, namely, the amount we receive in the Eucharist.
Now, when Martin Luther got a hold of this, he argued that the Catholic church was doling out the ‘extra’ blood that was not necessary to be spilled by Christ. He says that the church claimed to have the ‘extra’ blood, and could give it out as needed to cover for the new sins (after Jesus’ death) in the form of indulgences.
I believe the Catholic interpretation is correct regarding the ‘extra’ blood and the interpretation of the Eucharist. God gave us the extra blood of Christ, and this is made available to us in the Eucharist, and washes clean (gives new life) to those who suffer from these new sins. That is why he gave us the Eucharist.
The church becomes the Pelican and provides the cleansing blood of Christ in an ever replenishing supply that never runs out (the Eucharist). God explained this to us as he multiplied the loaves, and, when he showed his apostles how to give others his own blood.
Luther found this offensive and had to change Catholic doctrines and interpretation of the bible to make it go away.
Luther could not accept that God would give us this ability, to be so intimately linked to him. And also, there were those in the Catholic church that abused this power for personal profit so his objectives were based on real issues.
So I don’t agree with you that a Pope said that: ‘although shedding one drop of Christ’s would have been sufficient to save the human race, he suffered pain and death on the cross to demonstrate his love for us’ That seems to contain a theological error and I doubt that a Pope actually said it. The theological error is to say that the death of Christ was not necessary. In fact it was according to Aquinas.
Our Father (like a Pelican) gives us ALL of his life. He dies in his effort to save us. That is his message to us through Jesus. The death of Jesus was necessary. To say that his death was unnecessary does not fit with Catholic doctrine and is un-biblical.
So I assume the quote came from a protestant source, supposedly quoting the Catholic church, to re-enforce their objection to the Eucharist.