Love One Another: The Commandment That Changes Everything

There is a moment in the Gospel of John that is unlike almost any other in Scripture. Jesus, knowing that his hour had come, knowing that betrayal was already in motion, knowing that the cross was hours away, knelt on the floor and washed the feet of his disciples. He, the teacher and Lord, wrapped a towel around his waist and performed the task of the lowest servant in the household. Then he stood, looked at the men gathered around that table, and said: do you understand what I have done for you?

That question still echoes across the centuries. And the answer he gave them that night is one of the most profound and demanding truths in all of the New Testament.

A New Kind of Command

In John 13:34-35, Jesus issues what he calls a new commandment: that his followers love one another just as he has loved them, and that by this love, all people will know they are his disciples. At first glance, this might seem familiar. The Old Testament had already called God's people to love their neighbors as themselves, as recorded in Leviticus 19:18. So what exactly makes this new?

The newness is in the standard. The old command called people to love their neighbors as they loved themselves. Jesus raises the bar entirely. The measure of love he sets before his followers is not self-love, but Christ-love. He loved his own better than he loved himself, to the point of laying down his life for undeserving sinners. That is the standard. That is what he calls his people to reflect toward one another.

This is also a love that flows from a new nature. Those who belong to Christ are new creations, born again by the Spirit of God. The love Jesus commands is not simply a moral improvement on ordinary human affection. It is something qualitatively different, a love that springs from a transformed heart, produced by the indwelling Holy Spirit. It is the love of new people, living in a new relationship, bound together in a new family.

And that family is permanent. The ties of grace run deeper than the ties of blood. Brothers and sisters in Christ who may never share a surname will share eternity together. That reality ought to shape how seriously believers take their love for one another.

A Testimony the World Cannot Ignore

Jesus does not present this commandment as a private spiritual exercise. He frames it explicitly as a witness to the world. In John 13:35, he says that all people will know his disciples by their love for one another. The love of the church is meant to be visible, recognizable, and distinct enough that it points clearly to Christ.

The Apostle John returned to this theme decades later in his first epistle. In 1 John 3, he draws a direct line between love for one another and belonging to God, contrasting it with the way of the world. He pushes past sentiment and into action, insisting in 1 John 3:18 that love must show itself not in words alone but in deed and in truth.

This is where the stakes become very high. The world is watching the church. And what it often sees instead of the love Christ commanded is division, criticism, and fracture. Church splits, public arguments among believers, and the spectacle of Christians tearing one another apart in public spaces all send a message to a watching world, and it is not the message of the Gospel. When believers fail to love one another, they obscure the very testimony they are called to bear.

But when a community of Christ-followers genuinely loves one another, something remarkable happens. People notice. They are drawn in not by programs or polished presentations, but by the unmistakable presence of something they cannot manufacture on their own. The love of Christ, lived out in a community of believers, is one of the most powerful evangelistic forces in the world.

An Assurance for the Soul

There is a third dimension to this commandment that is easy to overlook. Loving one another is not only a duty and a witness. It is also a source of deep spiritual assurance.

In John 15:11, just a short time after issuing the new commandment, Jesus tells his disciples that he has spoken these things so that his joy may be in them and their joy may be full. Loving one another is connected directly to fullness of joy. It is not a burden that drains. Practiced in the Spirit, it is a gift that fills.

First John 4 presses this further. As believers love one another, they are told that God abides in them and his love is perfected in them. The practice of love toward one another becomes a means by which believers experience the reality of God's presence. And in 1 John 3:19, the same love provides reassurance to the heart, grounding the believer in truth and quieting the doubts that so often rise up from within.

This is the remarkable economy of the Kingdom. The love that God commands is also the love he supplies through his Spirit. And as that love flows outward toward brothers and sisters in Christ, it circles back as joy, assurance, and the deep settled knowledge that God is at work.

The Invitation

The commandment Jesus gave in that upper room was not meant to be admired from a distance. It was meant to be lived. He demonstrated it by kneeling on the floor with a basin of water. He sealed it by going to the cross.

The call for every follower of Christ is the same today as it was that night: love one another as Christ has loved you. Not as you love yourself. Not as the world loves. But with the self-giving, Spirit-empowered, eternally-grounded love of Jesus Christ himself.

And the promise attached to that love is just as alive today as it was then. The world will see it. The soul will be assured by it. And God will be glorified through it.

As 1 Thessalonians 4:9-10 reminds us, those who belong to God have been taught by God himself to love one another. The invitation is simply to do this more and more.