A person.

I have an interest in the things of G-d and He is my life. Through Him I have Life, I move, breathe and have my being. Yeshua is the way I express my love for G-d (the Father, I Am, יהוה)
It is through Yeshua's sacrifice that my debt was expunged and I am able to have a relationship with G-d.
It is through Yeshua, and His resurrection power that I am able to do the things pleasing to G-d.
He has put His Ruach, Spirit of Holiness, within me to lead me into all truth.
I read His entire Word to know the things that are pleasing to Him, and for the washing and renewing of my mind. Those who believe we are under a new covenant instead of being grafted in as the Word says are in error as they don't understand who the covenant was given to and how it was ratified.
Furthermore they divorce Yeshua from 39 books which contain His Words. From the beginning--as the book of John states--was the Word.

If you truly have been born again and made a new creation
then you will strive to keep the righteous commandments of G-d as the Torah is a pedagogue and once we have done it as we should through Yeshua and practice holiness as a way of life, then it can be written on our hearts.
How are we to have it on our hearts if we don't read it?
Because faith comes by hearing, how will you know if you do not hear? Yeshua said unless you are more stringent than those who teach the law (and you should know they were very stringent) then you will in no case enter Kingdom of Heaven. That is not to say that we earn salvation. It is through the free gift of G-d and not through works lest any man boast, but unless we do as He bids us, and that is following His good and righteous will, He will say, depart you worker of iniquity/unrighteousness...