Leviticus 18

Conjugal chastity accords with the written law by reason of the divine statute, Leviticus 18. For the Lord established laws according to which legitimacy is observed in the persons who contract marriage. For He says: I am the Lord your God: keep my laws and judgments, which if a man do, he shall live in them. No man shall approach to her that is near of kin to him, etc. Since therefore the Lord as a benefit promised that He would give offspring to Abraham through the way of marriage, and miraculously made fruitful the dead womb of Sarah, and also gave laws according to which marriage is to be contracted: it is evident that conjugal chastity accords with the written law.

The righteousness of the law, of which it is said that if a man does it he shall live in it, is set forth to this end: that every man may recognize his own infirmity. It is not in his own strength or through the letter of the law (which cannot be) but only by receiving through faith the favor of the Justifier that he may attain and do and live in righteousness.

For as many as are of the works of the law are under the curse: for it is written, Cursed is every one that continueth not in all things which are written in the book of the law to do them. But that no man is justified by the law in the sight of God, it is evident: for, The just shall live by faith. And the law is not of faith: but, The man that doeth them shall live in them. [Leviticus 18:5] Christ hath redeemed us from the curse of the law, being made a curse for us: for it is written, Cursed is every one that hangeth on a tree: That the blessing of Abraham might come on the Gentiles through Jesus Christ; that we might receive the promise of the Spirit through faith.

"The man who carries out the law will find life through it." Scripture did not say he will find life through it, in the sense that through the law he will live in heaven, but he will find life through it to the extent that what he merits, he reaps in the present world.

For the law promises those who practice it not the rewards of the heavenly kingdom but the consolations of this life when it says, "The one who does these things shall live in them." But the Lord says to his disciples, "Blessed are the poor in spirit, for theirs is the kingdom of heaven."

For Moses describeth the righteousness which is of the law, That the man which doeth those things shall live by them. [Leviticus 18:5] But the righteousness which is of faith speaketh on this wise, Say not in thine heart, Who shall ascend into heaven? (that is, to bring Christ down from above:) Or, Who shall descend into the deep? (that is, to bring up Christ again from the dead.) But what saith it? The word is nigh thee, even in thy mouth, and in thy heart: that is, the word of faith, which we preach; That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved. For with the heart man believeth unto righteousness; and with the mouth confession is made unto salvation. For the scripture saith, Whosoever believeth on him shall not be ashamed. For there is no difference between the Jew and the Greek: for the same Lord over all is rich unto all that call upon him. For whosoever shall call upon the name of the Lord shall be saved.