When Jesus stated that our righteousness must surpass that of the scribes and Pharisees, was He not alluding to the legal righteousness that would be imputed to us as a free gift? No, He was not, and for good reason. First, the context does not fit this interpretation. Before and after this statement (and throughout the entire Sermon on the Mount), Jesus was talking about keeping the commandments, that is, living righteously. The most natural interpretation of His words is that we must live more righteously than the scribes and Pharisees. And how absurd it would be to think that Jesus was holding the scribes and Pharisees to a standard to which He was not holding His own disciples. How foolish to think that Jesus would condemn the scribes and Pharisees for committing sins for which He would not also condemn His disciples simply because they had prayed a “salvation prayer.”
Our problem is that we don’t want to accept the obvious meaning of the verse, because it sounds to us like legalism. But our real problem is that we don’t understand the inseparable correlation between imputed righteousness and practical righteousness. The apostle John did, however. He wrote: “Little children, let no one deceive you; the one who practices righteousness is righteous” (1 John 3:7). Nor do we understand the correlation between the new birth and practical righteousness as John also did: “Everyone also who practices righteousness is born of Him” (1 John 2:29).
Jesus could have added to His statement of 5:20, “And if you repent, are truly born again, and receive through a living faith My free gift of righteousness, your practical righteousness will indeed exceed that of the scribes and Pharisees as you cooperate with the power of My indwelling Spirit.”
 Moreover, if Jesus was talking about the imputed, legal righteousness that we receive as a gift for believing in Him, why didn’t He at least hint at it? Why did He say something that would be so easily misunderstood by the uneducated people to whom He was speaking, who would have never guessed that He was talking about imputed righteousness?