Romans 10:5 : For Moses writeth that the man that doeth the righteousness which is of the law shall live thereby. This refers to what Moses said in Leviticus 18:5 : "Ye shall therefore keep my statutes, and mine ordinances which if a man do, he shall live in them." That meant strict adherence to all that the law said--perfect obedience to all its requirements. This no man ever did. Right-eousness would have been of the law if there had been perfect obedience to the law; and yet the law demanded just that. Its end, or purpose, is realized in Christ to all who believe. And that way of righteousness is not hard to understand, nor to practice.