What is the mark of a Christian? A fish on the back of a car? A cross worn around the neck? The right theology?
How easy it is to look in the wrong places for the sign of authenticity! Jesus told us plainly about the distinguishing mark of a Christian. He raises one quality above all others: “By this all men will know that you are my disciples, if you love one another” (John 13:35).
But what does this love look like? Jesus was concerned to leave an indelible, visual image in the minds of his disciples of what it means to love one another. He models servant-love by washing the disciples’ feet.
Greg Ogden, Discipleship Essentials: A Guide to Building Your Life in Christ, Expanded edition. (Downers Grove, IL: IVP Connect, 2007), 150.