Why is believing in Christ alone important for salvation?

The importance of faith in Christ alone lies in the totality of His redemptive work, which fulfills all that the law could not accomplish (Romans 8:3). Only through Christ can one attain true righteousness and peace with God. Any attempt to combine faith in Christ with works for salvation diminishes the grace of God and leads to a false assurance. True salvation is built on the foundation that Christ's sacrifice is sufficient, and nothing must be added to it of human effort or religious observance.