Not even this one law from the law could bring life or righteousness. It is not our goal to try to keep it or any lawful command attached with a condition. We have a new motivation as believers in Christ.
Paul begins to contrast the flesh with the Spirit. The flesh can sometimes look sinful and ugly, while at other times it may appear very religious and good outwardly. Jesus fulfilled the law; therefore, the better option is walking by the Spirit and being led by the Spirit in order to avoid all of the old and unprofitable law entirely ... including modernized versions of it.