Why is belief in Christ's ability to save important for Christians?

The message of salvation through Christ is central to the Christian faith. Hebrews 12:28 reminds us that we are receiving a kingdom that cannot be shaken. This assurance forms the foundation of our faith—believing that Christ's sacrifice is sufficient to secure our salvation and eternal life. Such belief not only gives us hope but also compels us to live in obedience and reverence, recognizing the gravity of God’s grace and His righteous judgment. Those who refuse to believe are warned of the gravity of turning away from such a great salvation.