How do we know salvation comes from Christ alone?

Salvation is a comprehensive term that reflects a work done for us and a work done in us. The Lord Jesus Christ had to undertake a work for sinners by paying their sin debt with His blood, which is foundational for salvation. However, another critical aspect lies in the necessity of a spiritual transformation within us. The new birth produces a new nature that resembles Christ, allowing believers to live in accordance with God's statutes. Without this inner work initiated by God, no one can be saved. This proves, unmistakably, that salvation is entirely dependent upon Christ and His grace.