11 Accordingly, after saying, “Now shall the prince of this world be cast out,” He added, “And I, if I be lifted up from the earth, will draw all things after me.” And what “all” is that, but those out of which the other is ejected? But He did not say, All men, but “all things;” for all men have not faith. And, therefore, He did not allude to the totality of men, but to the creature in its personal integrity, that is, to spirit, and soul, and body; or all that which makes us the intelligent, living, visible, and palpable beings we are.
For He who said, “Not a hair of your head shall perish,” is He who draws all things after Him. Or if by “all things” it is men that are to be understood, we can speak of all things that are foreordained to salvation: of all which He declared, when previously speaking of His sheep, that not one of them would be lost. And of a certainty all classes of men, both of every language and every age, and all grades of rank, and all diversities of talents, and all the professions of lawful and useful arts, and all else that can be named in accordance with the innumerable differences by which men, save in sin alone, are mutually separated, from the highest to the lowest, and from the king to the beggar, “all,” He says, “will I draw after me;” that He may be their head, and they His members.
But this will be, He adds, “if I be lifted up from the earth,” that is, when I am lifted up; for He has no doubt of the future accomplishment of that which He came to fulfill. He here alludes to what He said before: “But if the grain of wheat die, it brings forth much fruit.” For what else did He signify by His lifting up, than His suffering on the cross, an explanation which the evangelist himself has not omitted; for he has appended the words, “And this He said signifying what death He should die.”
Source: Tractates on the Gospel of John (New Advent)