God’s word is replete with passages that remind us that man, fallen into his sin nature, is incapable of doing good apart from God in his life. Without Him, our righteousness (doing right, doing good) is as filthy rags (Isaiah 64:6) and because no one is righteous (Romans 3:10), we cannot reach God because we cannot measure up to His holy standard (Romans 3:23). No matter how hard or earnestly we try, we cannot establish a relationship with God on our own.

This means we can’t “clean ourselves up” to approach a righteous and holy God. We cannot earn His favor nor His salvation through “living a good life” or by working our way with good deeds.

The Christian life, then, cannot begin with attempting “acceptable” behavior but with belief. Before we can walk in the light or bear the fruit of obedience, we must first be born again. And that birth begins with believing in Jesus the Christ, the Anointed One, the Promised Messiah.

John opens his letter with clarity and conviction. He writes to those who have heard, seen, and received the truth about Jesus — the eternal Son of God, made flesh (1 John 1:1–3). This is not a vague spirituality or moral philosophy. It is a concrete confession: Jesus is the Christ, the Son of God, sent to save sinners and restore fellowship with the Father.

Belief in Jesus is not merely intellectual assent. It’s more than simply agreeing with facts about who Jesus is. It’s entrusting your life to a Person. It’s acknowledging His lordship, receiving His grace, and surrendering to His authority. John says that everyone who believes that Jesus is the Christ is born of God (1 John 5:1). That belief initiates a spiritual rebirth — a new nature, a new identity, and a new relationship.

This is the foundation of assurance. Without belief in the Son, there is no life (1 John 5:12). But with Him, there is eternal life, fellowship, and joy. John writes so that believers may know they have eternal life — not hope, not guess, but know (1 John 5:13). That knowledge is rooted in the person and work of Jesus.

Belief also brings fellowship. John emphasizes that those who believe are invited into communion with God and with one another (1 John 1:3). The gospel creates a spiritual family, united by faith and sustained by grace. This fellowship is not superficial. It’s transformative. It shapes how we live, love, and grow.

This belief is not static. It moves. It matures. It bears fruit. Those who truly believe begin to walk in the light, obey God’s commands, and love His people. These are not conditions for salvation but confirmations of it. The root is belief. The resultant visible fruit is transformation.

This is why John warns against false assurance. He speaks of those who claim to know God but deny the Son (1 John 2:22–23). Such belief is hollow. True faith embraces Jesus fully with His identity, His mission, and His message. To reject the Son is to reject the Father. But to receive the Son is to receive life.

Belief also brings victory. John writes that everyone born of God overcomes the world — its temporal, fleeting rewards that perish — and this victory comes through faith (1 John 5:4–5). Believers are not immune to struggle, but they are empowered to overcome. Faith anchors them. Grace sustains them. And the Spirit guides them.

So how do we cultivate this assurance?

We begin by examining the object of our faith. Are we trusting in Jesus or in ourselves? Are we resting in His finished work or striving to earn His favor? Assurance grows when our eyes are fixed on Christ, not on our inadequate performance.

Then we affirm the truth. Jesus is the Christ — the promised Messiah, the Son of God, the Savior of the world. He lived, died, and rose again to reconcile us to the Father. This is the gospel. This is our hope. This is our foundation.

And finally, we respond with surrender. Belief is not passive — it’s active. It leads to repentance, obedience, and love. It reshapes our priorities, renews our minds, and redirects our steps.

Belief in Jesus is the starting point of the Christian life. It’s the foundation of assurance, the gateway to fellowship, and the source of transformation. Everything else flows from this. Without belief, there is no life. But with belief, there is everything.