“For Christ has already accomplished the purpose for which the law was given.^[a] As a result, all who believe in him are made right with God.  For Moses writes that the law’s way of making a person right with God requires obedience to all of its commands.” Rom. 10:4-5, NLT. 

Legalism can come in many forms, some more subtle than others. Those who look to themselves, to their good deeds, their Bible knowledge, their ecstatic utterances, to their diet, to all the bad things they don’t do, or to the good things that they have achieved – even with the best of intentions – are falling into the trap of legalism. Anything that causes you to look to yourself for evidence of salvation is legalism. Every moment of our lives, we must keep before us the holiness of God in contrast to our sinfulness; that’s the surest way to protect ourselves from the kind of thinking that leads people into seeking their “own righteousness,” which is contrary to the righteousness of Christ. 

Romans 10:4 is an important text that catches the essence of Paul’s entire message to the Romans. First, we need to know its context. Many Jews were “going about to establish their own righteousness” (Rom. 10:3) and seeking “the righteousness which is of the law” (Rom. 10:5 NASB). But with the coming of the Messiah, the true way of righteousness was presented. Righteousness was offered to all who would fix their faith in Christ. He was the one to whom the ancient ceremonial system had pointed. Notice he did not say Christ is the end of the Law, but that “Christ is the end of the Law for righteousness.” (10:4 NASB, NKJV etc)  

Paul is here demonstrating that his view of justification by faith is not something new, but has always been God’s way of accepting people. He makes his point by assembling a series of OT passages. (Remember, Paul Got his doctrine of ‘justification by faith alone, without the works of the law’ from the Old Testament.)  

His first quotes Leviticus 18:5, which means to him that the person who desires to establish righteousness by keeping the law must live up to all aspects and details of the law. That is, it must be obeyed to the very letter with absolute perfection! Anything less than that means no salvation since the law contains no inherent grace, forgiveness or mercy. (c.f. James 2:10) 

Paul has already demonstrated from the Jewish Scriptures themselves that all have sinned and have fallen short of God’s glory (Rom.3:9-20, 23). Thus, at their very best, even the most diligent human beings have been able to produce only imperfect and unacceptable righteousness according to the law. And in God’s sight such ‘righteousness’ is entirely unrighteous. 

Notice how the rich young ruler had no qualms in claiming that he had kept all of God’s commandments from the time of his youth (Matt.19:20). But Jesus soon exploded that deception when He put His finger on the man’s lack of concern for his neighbours. 

Paul has also consistently and repeatedly set forth God’s plan of salvation by grace through faith as the only alternative to salvation by human effort. The amount of time that he has spent on the topic indicates how deeply ingrained works-righteousness is in the human psyche.