The most amazing gift ever! This is how we know right from wrong, good from evil. We don't have to think about it, or write lists of pro and con. It is in our heart, it is on our lips. We know.

Deuteronomy 30:14

But the word is very near you, in your mouth and in your heart, that you may do it.
Bible Gateway link: Deuteronomy 30:14 (NKJV)