The heretic, Marcion, taught and believed that the God of the Old Testament was full of wrath while the God of the New Testament was full of grace and love. In his canon, his bible, he totally took out the Old Testament. While it is true in many ways that God's grace is more conspicuous in the New Testament, His love and grace are all over the Old Testament as well. This passage teaches us much about what true love looks like in the light of God's love.
God commands His people to keep His Law, statutes, rules, and commandments. However, what does He want to be our motivation for doing so? He tells us that we are to love the Lord our God and obey Him. In the prologue to the 10 Commandments, God reminds His people about His deliverance of them from Egypt and of His love and commitment to them. He tells them this before giving the first command.
God speaks of the relationship that He has established with them as the basis of His telling them how they should live. Who would not want to obey such a loving, holy, and perfect Father? Look at how God fought for them and delivered them. Think of how God carried His people through the wilderness as a father carries a son in his arms. Think of how God poured out His Son, who knew no sin, to become sin, in order that we might become the righteousness of God.
Notice the significant emphasis upon the heart. According to Scripture our hearts are the real US that only God can see. Our hearts are the seat of our emotions. Our hearts are the place of true worship and devotion. God knows that even as His children the affections of our hearts can go after things or people that we allow to become bigger than God Himself in terms of our worship, love, and devotion. This is why God constantly warns His children about the dangers of false gods and idols.
Our hearts are idol factories and God sees them and knows that while we profess true faith in Him we also have functional idols that we trust in for comfort, peace, and significance. We can be tempted to pursue counterfeit glories. God wants us to obey Him with all we are, with all of our heart, soul, mind, and strength. This is life.