The reality of God was never something I’ve really questioned. Sure, I’ve doubted the nature of God, the person of God, and my relationship to this God. In the end, the deciding question for me was whether this divine being would have any implications for my life.

Beloved, I am writing you no new commandment, but an old commandment that you had from the beginning. The old commandment is the word that you have heard. At the same time, it is a new commandment that I am writing to you, which is true in him and in you, because the darkness is passing away and the true light is already shining. Whoever says he is in the light and hates his brother is still in darkness. Whoever loves his brother abides in the light, and in him there is no cause for stumbling. But whoever hates his brother is in the darkness and walks in the darkness, and does not know where he is going, because the darkness has blinded his eyes.

— 1 John 2:7–11 (ESV)

There are plenty of people who call themselves Christians. Yet, there’s a huge diversity and range of how that is expressed in their lives. Is it based on how often they attend church? Is it based on how much money they give to charity, the church, and mission? Is it based on how much of the Bible they know? How do we tell the difference between a Christian who knows God? And one only in name?

The old commandment

What is John’s new, old commandment? Let’s start with the old.

You shall love the LORD your God with all your heart and with all your soul and with all your might.

— Deuteronomy 6:5 and Matthew 22:37

Also:

You shall love your neighbour as yourself: I am the LORD.

— Leviticus 19:18b and Matthew 22:39

For Jesus, He considered these to be the greatest commandment in the Old Covenant.

The new commandment

So, what’s the new commandment then?

A new commandment I give to you, that you love one another: just as I have loved you, you also are to love one another.

— John 13:34 (ESV)

Jesus sums up the greatest commandment of the Old in a new commandment. Though, it’s not really new. Rather, it’s foundation was new. In the Old Convenant, the foundation of the commandments was the sovereignty of God—I am the LORD.

So, what’s new? Jesus is. Jesus now provides the model of love. Just as I have loved you, you are to love one another. Jesus makes the old commandment new by demonstrating the extent of such love. A love that allowed Himself to be crucified on the Cross of Calvary!

The new, old commandment

Knowing God is the foundation for the commandments to love. In the old, to love God required your whole being—with all your heart and with all your soul and with all your might. Yet, there was still a degree of distance between a person and God.

However, Jesus bridges that distance. If we know Jesus, we know God (John 14:1-14). Yet both Jesus and John emphasise this point—to know God is not simply a profession of faith. Actions and words must go hand in hand. Whoever says he is in the light and hates his brother is still in darkness. The Christian who knows God is marked by their actions, not merely their words. There must be integrity both in actions and words.

In J. I. Packer’s Knowing God, he writes:

There is nothing more irreligious than self-absorbed religion.

To truly know God, one must love God. If one loves God, he loves others, just as Jesus loves them. This love took Jesus to the cross, where will it take you?