The Great Commandment, or Greatest Commandment, is an appellation applied to either the first, or both, of two commandments which appear in Matthew 22:34-40, Mark 12:28-34 and Luke 10:25-28. Both commandments are taken from the Law of Moses in the Old Testament. When asked which commandment was the most important, the Bible reports Jesus as answering, "Thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind" before also referring to a second commandment, "Thou shalt love thy neighbor as thyself". This double reference has given rise to differing views with regard to the relationship that exists between the two commandments, although typically "love thy God" is referred to as 'the first and Greatest Commandment', with "love thy neighbor" being referred to as 'the second Great Commandment'.
34 When the Pharisees heard that he had silenced the Sadducees, they gathered together, 35 and one of them, a lawyer, asked him a question to test him. 36 “Teacher, which commandment in the law is the greatest?” 37 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.’ 38 This is the greatest and first commandment. 39 And a second is like it: ‘You shall love your neighbor as yourself.’ 40 On these two commandments hang all the law and the prophets.”
28 One of the scribes came near and heard them disputing with one another, and seeing that he answered them well, he asked him, “Which commandment is the first of all?” 29 Jesus answered, “The first is, ‘Hear, O Israel: the Lord our God, the Lord is one; 30 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.’31 The second is this, ‘You shall love your neighbor as yourself.’ There is no other commandment greater than these.” 32 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’; 33 and ‘to love him with all the heart, and with all the understanding, and with all the strength,’ and ‘to love one’s neighbor as oneself,’—this is much more important than all whole burnt offerings and sacrifices.” 34 When Jesus saw that he answered wisely, he said to him, “You are not far from the kingdom of God.” After that no one dared to ask him any question.
25 Just then a lawyer stood up to test Jesus. “Teacher,” he said, “what must I do to inherit eternal life?” 26 He said to him, “What is written in the law? What do you read there?” 27 He answered, “You shall love the Lord your God with all your heart, and with all your soul, and with all your strength, and with all your mind; and your neighbor as yourself.” 28 And he said to him, “You have given the right answer; do this, and you will live.”