Why is believing in Jesus Christ crucial for salvation?

In the context of salvation, belief in Jesus Christ is not merely intellectual assent but a deep, trustful reliance on His completed work. In John 5, the impotent man struggles with helplessness, and Jesus calls him to believe and be made whole. This illustrates that true faith depends on recognizing our inability and affirming Christ's ability to save us. Salvation is described as belief that Jesus is the one who paid it all, thus providing assurance that our standing before God is based on His righteousness, not our own efforts.