How do we know God's grace cannot be frustrated?

The concept that God's grace cannot be frustrated is rooted in the understanding of God's sovereign will. Before the world began, as referenced in 2 Timothy 1:9, God ordained grace for His elect. This means that no outside force can alter God's redemptive plan. Additionally, Romans 3:20-21 explains that righteousness from God comes not through the law but through faith in Christ, reinforcing that grace, rather than human effort, brings about salvation. Therefore, no action or failure of men can nullify God's purpose to save His chosen people.