The author of the book to the Hebrews, in chapter 12, verses 4-6 says:
In your struggle against sin you have not yet resisted to the point of shedding your blood. And have you forgotten the exhortation that addresses you as sons?
“My son, do not regard lightly the discipline of the Lord,
nor be weary when reproved by him.
For the Lord disciplines the one he loves,
and chastises every son whom he receives.”
Hebrews 12:4-6 English Standard Version (ESV)
Do you say, as I do sometimes: “Why should I struggle against doing my own will and instead do His will?” Or do we see ourselves as better than this One?
And he came out and went, as was his custom, to the Mount of Olives, and the disciples followed him. And when he came to the place, he said to them, “Pray that you may not enter into temptation.”
And he withdrew from them about a stone’s throw, and knelt down and prayed, saying, “Father, if you are willing, remove this cup from me. Nevertheless, not my will, but yours, be done.”
And there appeared to him an angel from heaven, strengthening him. And being in an agony he prayed more earnestly; and his sweat became like great drops of blood falling down to the ground.
And when he rose from prayer, he came to the disciples and found them sleeping for sorrow, and he said to them, “Why are you sleeping? Rise and pray that you may not enter into temptation.”
Luke 22:39-46 (ESV)
Some manuscripts leave out the verses in the third paragraph.
So, with regard to the verse:
And being in an agony he prayed more earnestly; and his sweat became like great drops of blood falling down to the ground.
what does John Calvin comment?
Certainly those who imagine that the Son of God was exempt from human passions do not truly and sincerely acknowledge him to be a man…
…When Christ was distressed by grief and fear, he did not rise against God, but continued to be regulated by the true rule of moderation. We need not wonder that, since he was innocent and pure from every stain, the affections which flowed from him were pure and stainless… Christ, amidst fear and sadness, was weak without any taint of sin…
…He [Christ] had no horror at death…simply as a passage out of the world, but because he had before his eyes the dreadful tribunal of God, and the Judge himself armed with inconceivable vengeance; and because our sins, the load of which was laid upon him, pressed him down with their enormous weight. There is no reason to wonder, therefore, if the dreadful abyss of destruction tormented him grievously with fear and anguish.
…And, therefore, though he suffered death, yet since its pains were loosed—as Peter tells us, (Acts 2:24)—and he was victorious in the conflict, the Apostle justly says, that he was heard on account of his fear [Hebrews 5:7]. Here ignorant people rise up and exclaim, that it would have been unworthy of Christ to be afraid of being swallowed up by death.
But I should wish them to answer this question, What kind of fear do they suppose it to have been which drew from Christ drops of blood? (Luke 22:44). For that mortal sweat could only have proceeded from fearful and unusual horror. If any person, in the present day, were to sweat blood, and in such a quantity that the drops should fall to the ground, it would be reckoned an astonishing miracle…
If it be objected, that the fear which I am describing arises from unbelief, the answer is easy. When Christ was struck with horror at the divine curse, the feeling of the flesh affected him in such a manner, that faith still remained firm and unshaken. For such was the purity of his nature, that he felt, without being wounded by them, those temptations which pierce us with their stings.
And yet those persons, by representing him not to have felt temptations, foolishly imagine that he was victorious without fighting. And, indeed, we have no right to suppose that he used any hypocrisy, when he complained of a mortal sadness in his soul; nor do the Evangelists speak falsely, when they say that he was exceedingly sorrowful, and that he trembled.
In the face of deep fear and anguish, Christ prayed earnestly that His Father’s will be done and He opened the way of salvation to all who will be saved. No matter what anyone says, resistance is not futile.
Borg transmission from the movie Star Trek VIII First Contact – English version