The Law Is The Word Of God

Romans 2:14 ESV 

For when Gentiles, who do not have the law, by nature do what the law requires, they are a law to themselves, even though they do not have the law.

The nature of the Gentiles which allows them to do what the law requires is the nature of Christ. He alone fulfills the law. This is manifest in the body of Christ through His Spirit. The law is the word of Christ. He fulfills the purpose of God from the beginning. He said His word would not return empty. 

God so loved the world that He brought His love into the world. 

Romans 13:9-10

9 For the commandments, “You shall not commit adultery, You shall not murder, You shall not steal, You shall not covet,” and any other commandment, are summed up in this word: “You shall love your neighbor as yourself.” 10 Love does no wrong to a neighbor; therefore love is the fulfilling of the law.

Isaiah 55:10-11

10 “For as the rain and the snow come down from heaven

and do not return there but water the earth,

making it bring forth and sprout,

giving seed to the sower and bread to the eater,

11 so shall my word be that goes out from my mouth;

it shall not return to me empty,

but it shall accomplish that which I purpose,

and shall succeed in the thing for which I sent it.