The prime teaching of Moses:
4. Hear, O Israel: The Lord is our God; the Lord is one.
5. And you shall love the Lord, your God, with all your heart and with all your soul, and with all your means.
6. And these words, which I command you this day, shall be upon your heart.
7. And you shall teach them to your sons and speak of them when you sit in your house, and when you walk on the way, and when you lie down and when you rise up.
8. And you shall bind them for a sign upon your hand, and they shall be for ornaments between your eyes.
9. And you shall inscribe them upon the doorposts of your house and upon your gates.
Deuteronomy - Chapter 6 (Parshah Va'etchanan) - Tanakh Online - Torah - Bible
This is the essence of all commandments and the Law of Moses;one who does not follow this teaching with all the emphasis made by Moses; does not in effect follow Moses.
regards