Which commandment in the law is the greatest?

When the Pharisees heard that he had silenced the Sadducees, they gathered together, and one of them, a lawyer, asked him a question to test him.

"Teacher, which commandment in the law is the greatest?"

He said to him, " 'You shall love the Lord your God with all your heart, and with all your soul, and with all your mind.' This is the greatest and first commandment.

And a second is like it: 'You shall love your neighbor as yourself.'

On these two commandments hang all the law and the prophets."