God describes the relationship with His people as a relationship of love (Deuteronomy 7:7-8, 10:15). The Shema prayer is a response to this relationship that is rooted and grounded in love:
“Hear, O Israel! The Lord is 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 might. These words, which I am commanding you today, shall be on your heart” (Deuteronomy 6:4-6).
God gave his instruction (Torah) not as a set of legalistic commands, but as a loving Father teaching His children. Love was always to be the basis of God’s relationship with His people (Deut 5:10, 10:12, 30:6).
So, what does it mean to “love the Lord your God with all your heart and with all your soul and with all your might?” How does one love the Lord in this total way? Judaism sees these three ways of loving the Lord exemplified in the lives of the Patriarchs: Abraham (all our heart), Isaac (all our soul), and Jacob (all our strength). Abraham believed God and lived his life as an expression of his faithful heart toward Him. He was also generous in his hospitality and in his concern for others. Isaac was willing to lay down his life, his entire being, as a sacrifice to God. Jacob saw how God’s kingdom was to be here on this earth and he committed all that he possessed to the service of God and His purpose.
This all-encompassing expression of loving God, our Father, is found in the teaching of Jesus (Mark 12:28-31, John 15:9-14).
The writers of the New Testament further testify that God, in His great love, has freely given us all that He is through Christ (Ephesians 1:3-7). Our response is to love Him with the totality of heart, soul, mind, and possessions (Luke 10:25-27). This total response to God’s love is expressed in our worship and sacrifice, and in our love and service to others (1 John 4:19-21).
Understanding Judaism: The Basics of Deed and Creed, Rabbi Benjamin Blech, Jason Aronson Inc., 1992 (114-120)