Man does nothing but fail God. God says nothing but “My grace is sufficient for you” (2 Corinthians 12:9). Grace was sufficient for Abraham though he took Hagar outside of the will of God (Genesis 16). God protected Ishmael and gave him an inheritance (Genesis 21:18). Jacob steals his brother’s birthright. Does he lose the privilege of it? No, he ends up hearing the words “Jacob have I loved” (Malachi 1:2) and with the assurance that God never imputes sin to a crooked Jacob (Numbers 23:21). David, despite his many sins, was called a man after God’s own heart. Lot was counted righteous in the New Testament age of mercy. Peter denied God three times to the point of cursing, and yet God used him. Saul accused and persecuted Christians, but grace knocked him down, called him to preach the unsearchable riches of Christ, and used him as the chief apostle to the Gentiles.
Grace does not become sufficient when people live up to God, but God’s grace is sufficient when we fail and can do nothing but allow His strength to be made perfect in our weakness. Satan wants us to think that grace is given based on a system of what we merit. But grace is Jesus being enough for every man who, in every situation, will trust the nature of love to be sufficient in the weakness of his character.
Why did Paul endure a thorn in the flesh (2 Corinthians 12:7)? God wanted Paul to discover the sufficiency of grace. The thorn reminded him of his frailty and thus drew him into the perfection of God’s strength.