Jesus was quoting Deuteronomy 6:5. It's the greatest commandment. But if you open your Bible to Deuteronomy 6:5, you might find that it says we are to love God with all of our heart, soul, and might. What about the mind? The NET translation doesn't say heart but instead says mind. What? Mark 12:30 records Jesus saying we should love God with all of our heart, soul, mind, and strength. Now there's four things? So our collective list includes heart, soul, mind, might, and strength. What's going on here?
If I were planning to write a 3-point sermon and choose three of the things with which we should love God, I'd have a problem. First, how are these things different in the three books? Second, dividing it up by three things would miss the actual point. So what's the point?
There's really not much of a discrepancy here. The Deuteronomy text has three Hebrew words. Two of those words are easy. They mean soul and strength, or power. The third words is a little tricky. It is a word that references the place where thoughts and emotions come from. In the early Hebrew culture, that place was the heart. Ideas were generated in the heart. Emotions came from the heart. Decisions were made in the heart. In our culture, we say ideas come from the mind and emotions come from the heart. But if you think about it, that's silly considering that our heart is a muscle that pumps blood and our ideas and emotions are produced in the brain. Like us, the Greeks had a slightly different idea about where ideas come from. So we find that the New Testament authors try to explain the concept with the words that best capture what was said.
The concept is not that we are to love Jesus with different categories of who we are. No. The idea is that we are to love God with everything that we are. All of us. Nothing missed. Not a single thing left out.
Why do we struggle so much with this? Why do we hold stuff back? Why do we fail to fully love? Why is it so difficult? The answer is sin. In fact, sin could be defined by the areas we withhold from God.
But God loved us so much, he sent his Son, Jesus Christ to live and die for us (and then defeat death and sin for us too). This is the answer to sin. (John 3:16). While we were still steeped in our sin, he love us and even died for us. (Romans 5:8) God fills us with his love (Romans 5:5). Then because of his love we are able to love him (1 John 4:19).
God commands us to love him, but we can't just simply love. It's not that easy. Instead, God changes us. He frees us from the bondage of our sin. And in transforming us, God makes himself more and more desirable. We find our love growing more and more the closer we are to God. So really, when God calls us to love him, he's really telling us to draw near to him and allow ourselves to be changed. What a loving and amazing God!
Soli Deo gloria!