You can't hear His words unless He speaks His words, when the priests, and bishops speak His words at Mass, they're in His Person.
The laws God put on our hearts are the Commandments.
Take the passage in context, brother:
24
Let what you heard from the beginning remain in you. If what you heard from the beginning remains in you, then you will remain in the Son and in the Father.*
25
And this is the promise that he made us: eternal life.
26
I write you these things about those who would deceive you.
27
As for you, the anointing that you received from him remains in you, so that you do not need anyone to teach you. But his anointing teaches you about everything and is true and not false; just as it taught you, remain in him.
They needed a teacher, in verse 24. They were taught, and not by Christ. It says if what you were taught from the beginning remains in you, and not what those who would deceive you teach; if the anointing you received remains in you, then you need no other teacher. So remain with what you were taught.