When we move beyond John’s Gospel to his epistles, we find the same two themes are also linked there. For example, the connection between belief and love is perfectly summarized in a single verse in the apostle’s first letter: “And this is his command: to believe in the name of his Son, Jesus Christ, and to love one another as he commanded us” (1 John 3:23).
But although these two themes are clear enough in John’s writing, we do not always notice that he is teaching us an important lesson regarding them: that the one spiritual quality affects the other.
Belief Increases Love
Notice what John says regarding the first aspect of this interaction – that of belief affecting love. In 1 John 4:19 the apostle tells us: “We love because he first loved us.” Although the word belief does not appear directly in this verse, the concept is obviously implied – we come to love God because we believe God first loved us.
John connects belief with love in many other verses in this letter – such as 1 John 5:1 where he tells us: “Everyone who believes that Jesus is the Christ is born of God, and everyone who loves the father loves his child as well.”
But John evidently did not feel the necessity to elaborate on the connection between belief and love, as it is not a difficult one to see for ourselves in our own personal experience: the more we come to see and understand God and believe in him and his nature, the more we come to love him. Put simply, the more we come to know God, the more we come to love him.
Love Increases Belief
But John also shows this principle is reciprocal: the more we love God, the more our belief is strengthened. Consider the following verses.
“Everyone who loves has been born of God and knows God. Whoever does not love does not know God, because God is love” (1 John 4: 7B).
In this case, love is mentioned first and then knowing God – our belief in him – comes as a result. It is easy to read over this verse without seeing the connection John is making, but it is clear once we focus on it. The apostle makes the same connection in other verses. For example:
“No one has ever seen God; but if we love one another, God lives in us and his love is made complete in us” (1 John 4:12).
What proof do we have of God? John asks. His answer is straightforward – if we truly love one another, then God is living in us and we experience him in our lives in this way. John looks at the other side of this situation a few verses later:
“… whoever does not love their brother and sister, whom they have seen, cannot love God, whom they have not seen” (1 John 4:20).
This obviously has vital relevance for Christian life and belief. As we come to love, John tells us, we come to experience God – and so to believe in him. Near the end of his letter, John unites the two principles of love and belief once again:
“In fact, this is love for God: to keep his commands… This is the victory that has overcome the world, even our faith” (1 John 5:3).
John is not alone in making this connection. The New Testament shows on many occasions that spiritual qualities, such as belief and love, do not exist in a vacuum. The apostle Paul, for example, wrote on how belief interacts with love: “…The only thing that counts is faith expressing itself through love” (Galatians 5:6). John’s epistles show the same truth from both directions – the more we come to truly believe, the more we will also love; and vice versa, the more we truly love, the more we will come to truly believe.
Ultimately, for John, love and belief cannot be separated. We cannot develop the kind of love God exhibits without believing, or truly know and believe God without loving. As has been wisely said, “Belief is the eye of love, love is the heart of belief.” Both are necessary for the eternal life that, John tells us, God has desired to give us from the beginning (1 John 2:24).
* See the chapter on these two themes in our free e-book Inside the Four Gospels.