"He will render to each one according to his works: to those who by patience in well-doing seek for glory and honor and immortality, he will give eternal life; but for those who are self-seeking and do not obey the truth, but obey unrighteousness, there will be wrath and fury." (Rom 2:6-8)
"If you want to enter life, obey the commandments." (Matt 19:17)
What are we to make of the above statements by Paul and Jesus? Both of these texts plainly state that eternal life will be granted those who obey God's commandments. Since we have been taught that salvation to be by grace alone through faith alone in Christ alone, how are we to interpret such passages? I take up this important issue because there were one or two questions regarding the legitimacy of the concept of "do this and live" in my essay "There May be More Than One Way to God".
It should be known that these law/gospel (two ways of salvation model) concepts I proposed in the essay are not my peculiar new invention but the classic understanding of salvation in Covenant Theology.
When we preach the law to a person we are, in effect, saying "do this and live". Scripture actually reveals two ways that one might be saved in the Bible. These two antithetical covenants can be filtered down to "Do this and live" (Leviticus 18:5; Romans 2:13; 10:5), and "The just shall live by faith" (Habakkuk 2:4; Romans 10:6; Galatians 3:11). These covenants are both based in the eternal covenant of redemption which was made in the eternal counsels of the Triune God (John 6:37-39). Both will come into play through the historical Christ. This first covenant was revealed in Eden as the original Adamic Covenant (or covenant of Works). In its most basic form it consisted of the command "Do not eat, or you will die." It is easy enough to see that if you restate P for ~P, you get "Do this and live." When Adam failed to live up to the terms of the covenant, he plummeted he and his posterity into the Curse of death. Now all who are "in Adam" are incapable of life through that original covenant. It should be noted that God also mentions, after the fall, that the way to the tree of life is blocked lest man eat and live. So there was a means by which Adam hypothetically could have avoided the fall, that is, by obedience to God for a period or perhaps by eating the tree of life.
When we trust in Him we are saved by someone who was not only sinless, but who obeyed the covenant of works perfectly, obeying where Adam failed (Rom 5). He lived the life we should have lived and died the death we justly deserve. So, in fact, the reason we can be saved by grace alone is because Jesus took it upon Himself to do for us what we could not do for ourselves (i.e. obey the Law - our salvation by His person and works). For fallen humanity no one is able to keep the Law because of original sin and total depravity, but in Him we are counted as having kept the Law (Rom 8:3,4). So there is nothing inherently wrong with God's original covenant with man; the problem, of course, is with humanity, who exist in the bondage of corruption.
So what are we to make of such passages as "He will render to each one according to his works: to those who by patience in well-doing seek for glory and honor and immortality, he will give eternal life" (Rom 2:6-7)?
This text is given to us by Paul in the context of building up a massive case for the universal sinfulness of both Jews and Gentiles alike; that all persons fall short of God's infinitely holy standard and are justly deserving death. So in this part of his argument, Paul is, in effect, explaining that that the covenant of "DO THIS AND LIVE" is placed before all humanity. But in what follows Paul tears down this edifice by showing that man is incapable of life by that covenant, so was pleased to make a second, commonly called the covenant of grace.
Being a human being "under the law" is a necessary part of the work Jesus did on our behalf. We could not be declared righteous apart from Christ's active obedience to the law. Being killed as an infant by Herod would not have done it. Jesus declared that he came "not to abolish the law but to fulfill it". That is, fulfill all of God's righteous demands that God commands of humans who are unable, due to sin, to accomplish themselves. Likewise to John the Baptist, Jesus said he should to be baptized by Him to "fulfill all righteousness." Jesus' humanity and law keeping is, therefore, an integral part of His work for us.
God calls us to do things that we are morally incapable of. Why? Because the covenant of works still stands ... even though we cannot fulfill it. God has given all men over to sin that have might have mercy on them all in Christ.
God has not rescinded His law which says "Do this and Live". We herald the law and the gospel to people (1) to let them know that they must obey the commandments of God perfectly to live. This is God's requirement for mankind. But (2) when persons recognize they are morally impotent to obey, then the law serves its convicting purpose. They then, seeing their own inability and spiritual bankruptcy, can only flee to Christ for salvation.
I think perhaps some may have difficulties with the concept of "do this and live" because of the doctrine of original sin. They know that man is a sinner by nature, and before a man does or doesn't do anything, he is guilty of sin in Adam - therefore, they have a hard time reconciling this (which is true) and the fact that God commands people to "do this and live..." because they see it as a less than genuine thing on God's part, for He knows they are already guilty (Rom 5:12). But God commands things in his law all the time which we are incapable of doing, and that is its purpose, that we might despair of all hope in our own resources (Rom 3:20)
"For all who rely on works of the law are under a curse; for it is written, 'Cursed be everyone who does not abide by all things written in the Book of the Law, and do them.'" (Galatians 3:10)
"For God has done what the law, weakened by the flesh, could not do. By sending his own Son in the likeness of sinful flesh and for sin, he condemned sin in the flesh, in order that the righteous requirement of the law might be fulfilled in us..." (Rom 8:3,4)