How do we know that grace is essential for salvation?

Grace is foundational for salvation as it underscores the unmerited favor of God bestowed upon sinners. Ephesians 2:8-9 illustrates this by stating that we are saved by grace through faith, and that not of ourselves—indicating that salvation cannot be achieved through human works. Furthermore, Romans 5:8 reveals God's love in that Christ died for us while we were still sinners, showing that salvation is entirely based on God's grace rather than our own efforts or righteousness. The grace of God is what empowers believers to trust in Christ, leading to their justification.