One of them [Pharisees}, 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.'" Matthew 22:35-40
The Pharisees were at it again. They were trying to test Jesus. If they really only knew who they were talking to (the One who created them, gave them life, and knew exactly what was in their hearts)! Nothing they tried (when trying to trip him up) worked.
He answers their question by subtly pointing his finger (figuratively) back at them. They were the ones that probably lacked a love for God and others. They were the ones who were more concerned about keeping the Law rather than practicing mercy and justice. They were the ones who loved the people's praises. He was merely reminding them (and us) what we should be doing along the way in life.
If we only practiced these two commandment every day, life would go very well for us. It's good to be reminded this often because we forget.