These are the commands, decrees and laws the LORD your God directed me to teach you to observe in the land that you are crossing the Jordan to possess,
so that you, your children and their children after them may fear the LORD your God as long as you live by keeping all his decrees and commands that I give you, and so that you may enjoy long life.
Hear, O Israel, and be careful to obey so that it may go well with you and that you may increase greatly in a land flowing with milk and honey, just as the LORD, the God of your fathers, promised you.
Hear, O Israel: The LORD our God, the LORD is one.
Love the LORD your God with all your heart and with all your soul and with all your strength.
These commandments that I give you today are to be upon your hearts.
Deuteronomy 6:1-6 (NIV)
Hearing that Jesus had silenced the Sadducees, the Pharisees got together.
One of them, an expert in the law, tested him with this question:
"Teacher, which is the greatest commandment in the Law?"
Jesus replied: "'Love the Lord your God with all your heart and with all your soul and with all your mind.'
This is the first and greatest commandment.
And the second is like it: 'Love your neighbor as yourself.'
All the Law and the Prophets hang on these two commandments."
Matthew 22:34-40 (NIV)