2 “When Jesus knew,” then, “that His hour had come that He should pass out of this world unto the Father, having loved His own who were in the world, He loved them unto the end.” In order, doubtless, that they also, through that love of His, might pass from this world where they now were, to their Head who had passed hence before them. For what mean these words, “to the end,” but just to Christ? “For Christ is the end of the law,” says the apostle, “for righteousness to every one that believes.” The end that consummates, not that consumes; the end whereto we attain, not wherein we perish.
Exactly thus are we to understand the passage, “Christ our passover is sacrificed.” He is our end; into Him do we pass. For I see that these gospel words may also be taken in a kind of human sense, that Christ loved His own even unto death, so that this may be the meaning of “He loved them unto the end.” This meaning is human, not divine: for it was not merely up to this point that we were loved by Him, who loves us always and endlessly. God forbid that He, whose death could not end, should have ended His love at death.
Even after death that proud and ungodly rich man loved his five brethren; and is Christ to be thought of as loving us only till death? God forbid, beloved. He would have come in vain with a love for us that lasted till death, if that love had ended there. But perhaps the words, “He loved them unto the end,” may have to be understood in this way, That He so loved them as to die for them. For this He testified when He said, “Greater love has no man than this, that a man lay down his life for his friends.” We have certainly no objection that “He loved them unto the end” should be so understood, that is, it was His very love that carried Him on to death.
Source: Tractates on the Gospel of John (New Advent)