One of the scribes came near and heard them disputing with one another, and seeing that Jesus answered them well, he asked him, 'Which commandment is the first of all?' Jesus answered, 'The first is, "Hear, O Israel: the Lord our God, the Lord is one; you shall love the Lord your God with all your heart, and with all your soul, and with all your mind, and with all your strength." The second is this, "You shall love your neighbour as yourself." There is no other commandment greater than these.'
Then the scribe said to him, 'You are right, Teacher; you have truly said that "he is one, and besides him there is no other"; and "to love him with all the heart, and with all the understanding, and with all the strength", and to "love one's neighbour as oneself", - this is much more important than all whole burnt-offerings and sacrifices.' When Jesus saw that he answered wisely, he said to him, 'You are not far from the kingdom of God.'
(New Revised Standard Version)
Over 40 years ago I remember preaching a sermon on The Great Commandment, but obviously completely missed the mark as a woman came to speak to me afterwards, and she was absolutely furious. She read me a lecture about their being only Ten Commandments, and it was ridiculous to talk about another Commandment.
The Jewish Law contains at least 600 different rules and regulations, but in the time of Jesus it was common for scholars to try and distill this down to more basic principles. Hillel the Elder a famous Religious Leader born before Jesus, once said: "That which is hateful to you, do not do to your fellow. That is the whole Law, the rest is the explanation; go and learn."
The words that Jesus uses in this reading from Mark's Gospel don't come from the Ten Commandments, but from the prayer said daily by Jews found in Deuteronomy and Leviticus. We need to notice that he doesn't just recommend that we love God, but demands that we love Him and our neighbour. I admit to sometimes not loving my neighbour (as at the end of the sermon all those year's ago), but I do start each day with a confession to God of where I went wrong yesterday and a request to help me carry out the Great Commandment in the new day. It's a case of "Try, try, try again!"
Lord God,
You know our frailties and our sins;
You know our mistakes and our deliberate acts.
Help us to acknowledge these faults,
and try to live the kind of life
You want us to live -
loving You and our neighbour.
Amen.