Two laws and duality in the Bible:

The laws of God: the law of faith worketh righteousness, the law of deeds worketh wrath (Romans 4:15).  Hebrews 4:12 compares the word of God to a twoedged sword. Where twoedged means having a double mouth.  Going deeper into the meaning of that, it says the word of God has two meanings (double mouthed), hence the duality.   Revelation, in various places, speaks of a sword with two edges and a sharp sword coming out of the mouth of the Lord.   This sword of the mouth [or sword of words] can breed the law of deeds or the law of faith that worketh to love and righteousness. 

The first mention of a sword in the Bible is in Genesis 3:24 where is says a “flaming sword ...

What law do we follow?

Romans 3:20 “Therefore by the deeds of the law there shall no flesh be justified in his sight: for by the lawis the knowledge of sin.”  The law described here is the law of dos and don’ts and rights and wrongs. This laws tells us we are bad, and it says here we are not justified by our efforts to be “good” in the eyes of this law. It shows us our faults.

Romans 3:27-28  “Whereis boasting then? It is excluded. By what law? of works? Nay: but by the law of faith. Therefore we conclude that a man is justified by faith without the deeds of the law.”

It says here that a man is justified by the LAW OF FAITH not the LAW OF WORKS. There are two different laws spoken ...