In Matthew 22:37-40, of the New International Version, we read the following.
Jesus replied: “‘Love the Lord your God with all your heart and with all your soul and with all your mind.’ This is the first and greatest commandment. And the second is like it: ‘Love your neighbor as yourself.’ All the Law and the Prophets hang on these two commandments.”
How does the moral law “hang on” these two commandments? For instance, can we use these two commandments to decide that premarital sex is immoral? No, but they do tell us that there is an objectively correct answer to the question and God has determined the objectively correct answer.
To love is to will the good of the other. We cannot choose that things good for God happen to God for nothing bad could happen to God So, to will good for God is to will, or always try to will, the good God wills. The good God wills for people is lives in accordance with the moral laws since lives in accordance with moral laws are good lives for humans. For God always wills what is good.
Next, to love our neighbors as ourselves is to will for them the same good life we will for ourselves when we correctly will what is good for ourselves. Hence, to love our neighbors as ourselves is to will, or try always to will, that all of us live in accordance with the moral laws God has laid out for human beings.
The limits of the two laws of love are that they do not tell us any definite moral rules. And, of immense significance, they do not tell us that any feelings of love are a guide to morally correct behavior. The importance of the laws of love are that they tell us that there are objectively true moral answers and getting and following these right answers lead to good human lives.