When asked which was the greatest commandment, Jesus responded:
… Thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind. This is the first and great commandment. And the second is like unto it, Thou shalt love thy neighbour as thyself. On these two commandments hang all the law and the prophets. (Matthew 22:37-40, KJV)
“Law” and “prophets” are specific references in this context: the Hebrew Bible or Old Testament is called the Tanakh in Jewish tradition, an acronym for Torah (roughly “teaching” or “law”), Nevi’im (“prophets”), and K’tuvim (“writings”). The Torah is the first five books of Moses or Pentateuch; the Nevi’im the books that were eventually named after the prophets who (according to tradition) wrote them (e.g., Isaiah, Jeremiah, Amos, Haggai); and the K’tuvim are the Chronicles and poetic works like the Psalms, Proverbs, and Job. Although the Old Testament as we know it today wasn’t compiled until after the time of Christ – many scholars date the redaction and final closure of the OT canon to the first or second century after Jesus – the Torah and the Nevi’im, the law and the prophets, were pretty well established by Jesus’ time. He was saying, then, that the entirety of the Old Testament as he knew it – the sum of religion – lies in these two simple dicta: love God, and love each other.
And he was citing scripture as he said it. The injunction to love God is in the text of the ten commandments, and the requirement to love each other is repeated in various iterations in Leviticus:
Thou shalt not hate thy brother in thine heart … Thou shalt not avenge, nor bear any grudge against the children of thy people, but thou shalt love thy neighbour as thyself: I am the LORD. … But the stranger that dwelleth with you shall be unto you as one born among you, and thou shalt love him as thyself; for ye were strangers in the land of Egypt: I am the LORD your God. (Leviticus 19:17-18, 33-34, KJV)
Love everyone: strangers, neighbors, and kin, as yourself – and love God. It’s expansive, radical, and beautiful.
Rabbinic tradition clarifies the relationship between the two great commandments, arguing that there is no tension between the ideal to love your neighbor and the ideal to love God. Instead, they explain, we show our love of God through the act of loving others. In other words, God will never ask us to choose between loving Him and loving someone else; God asks us to demonstrate our faithfulness and devotion to Him through our faithfulness and devotion to others. He sees in our treatment of others the ultimate reflection of the love in our hearts.
On occasion I’ve heard Mormons comment on hypothetical areas of tension in this commandment of love: what should you do if you have to choose between God and your neighbor? or your spouse? or your child? I’ve listened to my fair share of talks in which people emote lengthily on the idea that, if given the choice between God and a spouse or God and a child, one should always choose God first. (I recall this idea being put forth often during my tenure at BYU as the loftiest litmus test of spousal selection: ideally, so sacrament speakers would suggest, your future spouse will tell you explicitly that he will always choose God first, even before you.) It is a hypothetical that I struggle to understand, and not just because of my childless, spouse-less state. I am persuaded that the rabbinical interpretation is the more accurate, and that it is more in tune with the teachings of Christ: we show our love of God through our love of spouses, children, neighbors, and friends. We show it through embracing, not rejecting; through compassion; through mourning with those that mourn and comforting those that stand in need of comfort.