Expositor's Bible Commentary Commentary John 13:35

"By this shall all men know that ye are my disciples, if ye have love one to another." — John 13:35 (ASV)

The most important instruction that Jesus left for the Eleven was this fresh, “new commandment”—to love one another. If their motive in following him had been to obtain a high place in the messianic kingdom (1:40, 49), Jesus knew that the spirit of rivalry would disrupt their fellowship before they could accomplish his commission to them. The attitude of love would be the bond that would keep them united and would be the convincing demonstration that they had partaken of his own spirit and purpose. He had loved them without reservation and without limit (13:1–5) and expected them to do the same.