The Great Commandment / The Shema:
“Hear, O Israel: The Lord our God is one Lord; and you shall love the Lord your God with all your heart, and with all your soul, and with all your might. And these words which I command you this day shall be upon your heart; and you shall teach them diligently to your children, and shall talk of them when you sit in your house, and when you walk by the way, and when you lie down, and when you rise. And you shall bind them as a sign upon your hand, and they shall be as frontlets between your eyes. And you shall write them on the doorposts of your house and on your gates.” (Deut. 6:4-9)  This is the “Great Commandment,” that you should love the Lord, your God, with all you heart, soul and might.  The Shema (Hebrew for “hear”) is written in Jewish phylacteries and bound to their heads and hands, as well as on the doorpost, or the mezuzah.

Jesus Quotes the Shema:
Jesus too quotes the Shema saying: “And one of the scribes came up and heard them disputing with one another, and seeing that He answered them well, 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; and 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.’” (Mk. 12:28-30)  It is interesting to note too that Jesus adds one line to the Shema saying we should love God “with all your mind.” The Law is not meant to be a mechanical following of rules and regulations, but rather, it is a Covenant, which is meant to be a heartfelt relationship with God. The Shema expresses this. It is a summation of the whole Law itself.

Jesus Rebukes Satan with Deuteronomy:
Jesus rebuked Satan in His tempting in the desert wilderness. Jesus answered Satan with quotes from Deuteronomy:

1. “You shall fear the Lord your God; you shall serve him, and swear by his name.” (Deut. 6;13)
2. “You shall not put the Lord your God to the test, as you tested him at Massah.” (Deut. 6:16)
3. “And he humbled you and let you hunger and fed you with manna, which you did not know, nor did your fathers know; that he might make you know that man does not live by bread alone, but that man lives by everything that proceeds out of the mouth of the Lord.” (Deut. 8:3)

Jesus shows the efficacy of the Old Testament scriptures, and that He has not come to erase the Law but to fulfill it; “For truly, I say to you, till heaven and earth pass away, not an iota, not a dot, will pass from the law until all is accomplished.” (Mt. 5:18)