How do we know that the gospel saves?

The gospel is described in Scripture as the 'power of God unto salvation' (Romans 1:16), which inherently confirms its efficacy in saving believers. This gospel is centered on Jesus Christ, His sacrificial death, and resurrection, which provides the groundwork for forgiveness of sins and eternal life. It is crucial to understand that this salvation is granted not by human effort or will, but through God's grace alone, as indicated in Ephesians 2:8-9. The gospel fundamentally changes the hearts of those who receive it, transforming them into new creations, as affirmed in 2 Corinthians 5:17.