How do we know that grace is the only basis for salvation?

According to Scripture, salvation is solely based on grace and not on human works. Ephesians 2:8-9 states that 'by grace you have been saved through faith, and that not of yourselves; it is the gift of God, not of works, lest anyone should boast.' This foundational doctrine underscores the idea that human effort or righteousness plays no role in our salvation; it is entirely an act of God's unmerited favor. The God of Glory, as revealed in Christ, chose to save a people for Himself out of pure grace, demonstrating that no one can achieve righteousness on their own. This grace was part of God's eternal covenant of mercy, planned before the beginning of the world.