But when the Pharisees heard that he had silenced the Sadducees, they came together. And one of them, a lawyer, asked him a question, to test him. "Teacher, which is the great commandment in the law?" And 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. This is the great and first commandment. And a second is like it. You shall love your neighbor as yourself. On these two commandments depend all the law and the prophets." Matthew 22:34–40 (RSV)
It is apparent to love the Lord you God with all your heart, soul, and mind. God is God, and He has commanded all things to be; thus, how could we not love Him? If He then bids us love our neighbor as ourselves, could we not also do this?
So simple and far beyond us that we might as well fly up to Mars and bring home a Martian. Only a liar would claim to love God with all their being at all times. Our broken and sinful nature cannot do this. Our self-love is so nearly complete; it is a miracle that we regard God at all, let alone the neighbor.
Yes, we write and sing of love constantly, but it is such a miserable thing next to the Father's love. Jesus rightly teaches us to take up our cross daily, letting our old nature die so that we might be raised a new creation. As the new creation, we forget what we say is love and seek after the love that flows from the abundance of true love with the Holy Trinity.
Within the divine love the Father grants us, we can begin to love God and our neighbor as we have been created to love. As we learn the selfless love of Christ, immersed in His holy love, we can begin to love as the Father has loved us. We begin to love our neighbor as we are loved in Christ.