20 And there were certain Greeks among them that came up to worship at the feast:
[AD 407] John Chrysostom on John 12:20
Being now near to become proselytes, they were at the Feast. When therefore the report concerning Him was imparted to them, they say,
[AD 407] John Chrysostom on John 12:20-26
(Hom. lxvi. 2) The time being now near, when they would be made proselytes. They hear Christ talked of, and wish to see Him: The same came therefore to Philip, which was of Bethsaida of Galilee, and desired him, saying, Sir, we would see Jesus.

(Hom. lxvii. 2) As being the elder disciple. He had heard our Saviour say, Go not into the way of the Gentiles; (Matt. 10:5) and therefore he communicates with his fellow-disciple, and they refer the matter to their Lord: And again Andrew and Philip tell Jesus.

(Hom. lxvi. 2) He illustrates His discourse by an example from nature. A grain of corn produces fruit, after it has died. How much more then must the Son of God? The Gentiles were to be called after the Jews had finally offended; i. e. after His crucifixion. Now then that the Gentiles of their own accord offered their faith, He saw that His crucifixion could not be far off. And to console the sorrow of His disciples, which He foresaw would arise, He tells them that to bear patiently not only His death, but their own too, is the only way to good: He that loveth his life shall lose it.

(Hom. lxvii. 1) He loveth his life in this world, who indulges its inordinate desires; he hateth it, who resists them. It is not, who doth not yield to, but, who hateth. For as we cannot bear to hear the voice or see the face of them whom we hate; so when the soul invites us to things contrary to God, we should turn her away from them with all our might.

(Hom. lxvii. 1) This present life is sweet to them who are given up to it. But he who looks heavenwards, and sees what good things are there, soon despises this life. When the better life appears, the worse is despised. This is Christ's meaning, when He says, If any man serve Me, let him follow Me, i. e. imitate Me, both in My death, and life. For he who serves, should follow him whom he serves.

(Hom. lxvii) So then death will be followed by resurrection. Where I am, He says; for Christ was in heaven before His resurrection. Thither let us ascend in heart and in mind.
If any man serve Me, him will My Father honour. This must be understood as an explanation of the preceding. There also shall My servant be. For what greater honour can an adopted son receive than to be where the Only Son is?

(Hom. lxvii) He says, My Father will honour him, not, I will honour him; because they had not yet proper notions of His nature, and thought Him inferior to the Father.

[AD 430] Augustine of Hippo on John 12:20-26
(Tr. li. 8) Lo! the Jews wish to kill Him, the Gentiles to see Him. But they also were of the Jews who cried, Blessed is He that cometh in the name of the Lord. So behold them of the circumcision, and them of the uncircumcision, once so wide apart, coming together like two walls, and meeting in one faith of Christ by the kiss of peace.
Philip cometh and telleth Andrew.

(Tr. li. 8) Listen we to the voice of the corner stone: And Jesus answered them, saying, The hour is come, that the Son of man should be glorified. Did He think Himself glorified, because the Gentiles wished to see? No. But He saw that after His passion and resurrection, the Gentiles in all lands would believe on Him; and took occasion from this request of some Gentiles to see Him, to announce the approaching fulness of the Gentiles, for that the hour of His being glorified was now at hand, and that after He was glorified in the heavens, the Gentiles would believe; according to the passage in the Psalm, Set up Thyself, O God, above the heavens, and Thy glory above all the earth. (Ps. 56, and 107) But it was necessary that His exaltation and glory should be preceded by His humiliation and passion; wherefore He says, Verily, verily, I say unto you, Except a corn of wheat fall into they round and die, it abideth alone: but if it die, it bringeth forth much fruit. That corn was He; to be mortified in the unbelief of the Jews, to be multiplied in the faith of the Gentiles.

(Tr. li. 10) This may be understood in two ways: 1. If thou lovest it, lose it: if thou wouldest preserve thy life in Christ, fear not death for Christ. 2. Do not love thy life here, lest thou lose it hereafter. The latter seems to be the more evangelical (evangelicus) sense; for it follows, And he that hateth his life in this world, shall keep it unto life eternal.

(Tr. li. 10) But think not for an instant, that by hating thy soul, is meant that thou mayest kill thyself. For wicked and perverse men have sometimes so mistaken it, and have burnt and strangled themselves, thrown themselves from precipices, and in other ways put an end to themselves. This did not Christ teach; nay, when the devil tempted Him to cast Himself down, He said, Get thee hence, Satanb. But when no other choice is given thee; when the persecutor threatens death, and thou must either disobey God's law, or depart out of this life, then hate thy life in this world, that thou mayest keep it unto life eternal.

(Tr. li) But what is it to serve Christ? The very words explain. They serve Christ who seek not their own things, but the things of Jesus Christ, i. e. who follow Him, walk in His, not their own, ways, do all good works for Christ's sake, not only works of mercy to men's bodies, but all others, till at length they fulfil that great work of love, and lay down their lives for the brethren. But what fruit, what reward? you ask. The next words tell you: And where I am, there shall also My servant be. Love Him for His own sake, and think it a rich reward for thy service, to be with Him.

[AD 444] Cyril of Alexandria on John 12:20
Anyone might be perplexed at these words and wonder with what motive certain Greeks should be going up to Jerusalem to worship. Note that they were doing this at the time when the feast was being celebrated according to the Law. For surely no one will say that they went up merely to look at the people there. Certainly it was with the intention of participating in the feast that was suitable for Jews and Jews only that they were journeying up in the company of the Jews. What was the point as regards the motive of worship that was common to both Greeks and Jews?…Since the territory of the Jews was situated near that of the Galileans, and since both they and the Greeks had cities and villages in close vicinity to each other, they were continually intermingling together and interchanging visits, being invited for a variety of occasions. And since it somehow happens that the disposition of idol worshipers is very easily brought to welcome a change for the better, and since nothing is easier than to convict their false worship of being utterly unprofitable, some among them were easily persuaded to change. This does not mean that they fully and perfectly worshiped him who alone is truly God, since they were somewhat divided with regard to the arguments in favor of abandoning idolatry and following the precepts of their own teachers.…
It was then a custom for certain of the inhabitants of Palestine, especially the Greeks, who had the territory of the Jews closely adjoining and bordering on their own, to be impressed in some way by the Jewish habits of thought and to honor the name of one sovereign [deity]. And this was the view current among those Greeks whom we just now mentioned, albeit they did not express it in the same way that we do. And they, not having the tendency to Judaism in full force, nor even having separated themselves from the habits dear to the Greeks but holding an intermediate opinion that inclined both ways, are called “worshipers of God.” People of this kind, therefore, seeing that their own habits of thought were not very sharply distinguished from those of the Jews … were in the habit of going up with the Jews to worship, especially at the national gatherings, not meaning to slight their own religion but as an act of honor to the one all-supreme God.

[AD 735] Bede on John 12:20-26
The temple at Jerusalem was so famous, that on the feast days, not only the people near, but many Gentiles from distant countries came to worship in it; as that eunuch of Candace, Queen of the Ethiopians, mentioned in the Acts. The Gentiles who were at Jerusalem now, had come up for this purpose: And there were certain Gentiles among them who came to worship at the feast.

He Himself, of the seed of the Patriarchs, was sown in the field of this world, that by dying, He might rise again with increase. He died alone; He rose again with many.

[AD 1107] Theophylact of Ohrid on John 12:20-26
As if they said, The more you attack Him, the more will His power and reputation increase. What use then of these attempts?

It were harsh to say that a man should hate his soul; so He adds, in this world: i. e. for a particular time, not for ever. And we shall gain in the end by so doing: shall keep it unto life eternal.