Law and grace are two opposite ways in which God deals with the human race. We can describe them as dissimilar principles under which He tests man. Or we think of them as two covenants that He has made with His people: "For the law was given by Moses, but grace and truth came by Jesus Christ" (John 1:17).
Under the principle of law, man receives what he earns or deserves. Under grace he is spared from what he deserves and is enriched beyond description-all as a free gift. The two principles are described in Romans 4:4, 5:
Now to him that worketh is the reward not reckoned of grace, but of debt. But to him that worketh not, but believeth on him that justifieth the ungodly, his faith is counted for righteousness.
Grace and law are mutually exclusive; that is, they cannot be mixed......... If by grace, then is it no more of works: otherwise grace is no more grace" (Rom. 11:6).
Law is a conditional covenant: God says, "If you obey, I will reward you, but if you disobey, I must punish you." Grace is an unconditional covenant: God says, "I will bless you freely."
The law says Do, whereas grace says Believe. But believing is not a condition; it is the only reasonable response of a creature to his Creator. And it is not meritorious; no one can be proud that he has believed on the Lord. He would be foolish not to believe on the only dependable Person in the universe.
Under law holiness is required but no power is given to live a holy life. Under grace holiness is taught (Tit. 2:11, 12) and the necessary power is given. Someone has put it this way: "The Law demands strength from one who has none and curses him if he can't display it. Grace gives strength to one who has none and blesses him in the exhibition of it."
The Law brings a curse: "Cursed is every one that continueth not in all things which are written in the book of the law to do them" (Gal. 3: 10). Grace brings a blessing: " Being justified freely by his grace through the redemption that is in Christ Jesus" (Rom. 3:24).
Under law boasting is encouraged, but under grace it is ruled out. "Then what becomes of our boasting? It is excluded. On what principle? On the principle of works? No, but on the principle of faith" (Rom. 3:27 RSV).
There cannot be any assurance of salvation under law: a man could never know whether he had performed enough good works or the right kind of good works. Under grace there is full assurance because salvation is a gift; you know when you have received a gift!
A person under law could not have true security because he could not be sure he would continue to meet the requirements. Under grace the believer enjoys eternal security (John 10:27-29) because his salvation depends on the work of Christ.
There is no salvation by the law. God never intended that anyone would ever be saved on that principle. The purpose of the Law is to show man that he is a sinner. " By the law is the knowledge of sin" (Rom. 3:20) -not the knowledge of salvation.
Salvation is by grace (Eph. 2:8,9). It is the free, undeserved gift of God to those who receive the Lord Jesus Christ as their only hope for heaven.
Under law sin is aroused (Rom. 7:8-13); under grace it is despised. When sinful man is put under law he immediately wants to do what is forbidden. It is not the law's fault, but the response of sin in man's nature. Under grace, sin is despised. The memory of what our sins cost the Savior makes us turn away from them.
Under law the work is never finished. That is why the Sabbath, the seventh day, came at the end of a week of toil. Grace tells us of a finished work, so we begin our week with the Lord's Day, our day of rest.
The Law tells what man must do. Grace reveals what God has done in Christ.
The Law is a system of bondage (Gal. 4:1-3); grace is a system of liberty (Gal. 5:1). Men under law are servants; men under grace are sons.
The Law says, "Thou shalt love." Grace says, "God so loved..."
The Law says, "Do and thou shalt live." Grace says, "Live and thou shalt do."
The Law says, "Try and obey." Grace says, "Trust and obey."
Under law a wayward son was taken outside the city and stoned to death (Deut. 21:18-2 1). Under grace the prodigal son can confess his sin and come back into the fellowship of his father's house again (Luke 15:21-24).
Under law the sheep die for the shepherd. Under grace the shepherd dies for the sheep (John 10:11).
The superiority of grace has been described as follows: grace is not looking for good men whom it may approve, for it is not grace but justice to approve goodness; but it is looking for condemned, guilty, speechless, and helpless men whom it may save, sanctify, and glorify.