The Law; the Word; HIS Christ is put in our hearts, minds and mouths.
This has been available since the time of Moses if not before through Christ. In Deut 30:6,10-14 GOD has said, And the LORD thy God will circumcise thine heart, and the heart of thy seed, to love the LORD thy God with all thine heart, and with all thy soul, that thou mayest live.If thou shalt hearken unto the voice of the LORD thy God (through this circumcision), to keep his commandments and his statutes which are written in
this book of the law (the word), and if thou turn unto the LORD thy God with all thine heart, and with all thy soul. For this commandment which I command thee this day, it is not hidden from thee, neither is it far off. It is not in heaven, that thou shouldest say, Who shall go up for us to heaven, and bring it unto us, that we may hear it, and do it? Neither is it beyond the sea, that thou shouldest say, Who shall go over the sea for us, and bring it unto us, that we may hear it, and do it? But
the word (the Book of the Law) is very nigh unto thee, in thy mouth, and in thy heart, that thou mayest do it.(Deu 30:6, 10-14 KJV)
This has always been GOD's intent. This what Christ fulfilled.
For 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 (the word, the Book of the Law)down from above
Or, Who shall descend into the deep? (that is, to bring up Christ (the word, the Book of the Law) again from the dead.) But what saith it? The word (Christ, the Book of the Law) is nigh thee, even in thy mouth, and in thy heart: that is, the word of faith, which we preach; For Christ (the word, the Book of the Law in our hearts and in our mouths) is the end of the law for righteousness to every one that believeth.
(Rom 10:6-8,4 KJV)