These things I command you, that you love one another.
All Commentaries on John 15:17 Go To John 15
Cornelius a Lapide
AD 1637
These things I command you, &c. He says these things in the plural to signify that there were indeed many particular precepts commanded by Him, but that all of them were included in the one common and easy precept of love, so that if one fulfils that, one fulfils all.
Secondly, You may explain more simply with S. Chrysostom if you take the conjunction that to signify the end. Then the meaning will be, These things which I have spoken concerning My love I have said with this only end in view, that ye should have mutual love among yourselves, and that thus ye should endure all things for the salvation of men. To this pertains the exposition of S. Augustine (Tract87), "Because He had said, I have placed you that ye should go and bear fruit, now He saith, These things I command you, wishing to teach that the fruit which we are to bear must be love of our neighbour." And again, "The fruit of the Spirit, saith the apostle, is charity. Concerning this therefore He gives commandment. Deservedly indeed does He often speak of love, as if it were the only thing to be commanded, as being that without which all other good things cannot profit, and which we cannot have without having all other good things by which a man becomes good with it."
