How do we know salvation is impossible for man?

The doctrinal understanding of mankind's inability to save themselves is rooted in the teaching of Scripture, which reveals that all have sinned and fall short of God's glory (Romans 3:23). Our sinful nature means that we are unable to fulfill the requirements of God's law on our own. This is further expanded upon when Scripture states that there is no one righteous, not even one (Romans 3:10). The only way one can be saved is through God's grace and mercy, making it clear that salvation is solely a divine act, unattainable by human means.