John 13:35

By this shall all men know that ye are my disciples, if ye have love one to another.
— John 13:35, King James Version

In other translations

World English Bible (WEB)

By this everyone will know that you are my disciples, if you have love for one another."

American Standard Version (ASV)

By this shall all men know that ye are my disciples, if ye have love one to another.

Young's Literal Translation (YLT)

in this shall all know that ye are my disciples, if ye may have love one to another.'