Jesus said, “Blessed are those who hunger and thirst for righteousness, for they shall be satisfied” (Matthew 5:6). The fourth beatitude deals with righteousness, which seems simple enough, but there is debate as to what Jesus means when He says “righteousness.” Is He talking about imputed righteousness, or is He talking about right behavior? David Turner argued Matthew (and Jesus) were not talking about imputed righteousness, which is a more Pauline concept. He wrote:
Protestant Christians who are used to reading Paul may think that Matthew is speaking of the imputed righteousness of Christ (cf., e.g., Rom. 5:1–2), but this forensic sense is not a Matthean nuance. Here the emphasis is on the practical side, the upright lifestyle (Turner, Matthew, 152).
Morris presents a more balanced view (and I believe a better view) of righteousness here in Matthew 5:6. He wrote:
Righteousness is often used in the New Testament for the right standing believers have before God because of Christ’s atoning work, but this is often said to be a Pauline concept rather than one that Matthew sets forth. Now it is plain that Matthew has a strong interest in the upright living that should characterize the servant of Christ, and we must not try to turn him into a pale shadow of Paul. But we must not minimize his emphasis on grace either (cf. v. 3). Specifically we should notice that he is not suggesting that people can make a strong effort and achieve the righteousness of which he is writing: it is a given righteousness, not an achieved righteousness. The blessed do not achieve it but hunger and thirst for it. They will be filled, which surely means that God will fill them (cf. 6:33, “his righteousness”) (Morris, Matthew, 99).
Morris acknowledges the practical aspect of righteousness, but he also emphasizes the positional dimension of righteousness. Christians are to seek to live righteous lives, but their righteousness is an imputed righteousness (not an earned righteousness).
If both of these aspects of righteousness can be seen in this verse, we should respond in two ways. First, we should praise God for the righteousness of Christ that has been imputed to us. It is not an earned righteousness; it is a received righteousness. Second, we should hunger and thirst for practical righteousness. That is, we should desire to live holy and righteousness lives…and Jesus says that those with this desire will be satisfied! God will enable those who desire to live godly to actually live godly!