Why is God's grace essential in salvation?

Grace is the cornerstone of salvation in sovereign grace theology. In Zechariah 3, God's grace is evident as He removes Joshua's filthy garments, symbolizing the forgiveness of sins, and clothes him with a change of raiment, representing Christ's righteousness. This reflects the truth found in Romans 3:24, where we are justified freely by God's grace through the redemption that is in Christ Jesus. Without grace, salvation would be unattainable, as no works of our own could merit God's favor (Ephesians 2:8-9).