What is the summary of God's moral law?

Answer 1

The summary is to love God with your whole heart, mind, strength and soul and to love your neighbor as yourself. Every other moral law or principle revolves around those 2 commandments given by Jesus Christ at Matthew 22:35-40 (New World Translationwhich contains the divine name): "After the Pharisees heard that he had silenced the Sadducees, they came together in one group. And one of them, versed in the Law, tested him by asking: "Teacher, which is the greatest commandment in the Law?" He said to him: "'You must love Jehovah your God with your whole heart and with your whole soul and with your whole mind.' This is the greatest and first commandment. The second, like it, is this: 'You must love your neighbor as yourself.' On these two commandments the whole Law hangs, and the Prophets."

Answer 2

Catholic Answer:

Luke 10:27: And he answered, "You shall love the Lord your God will all your heart, and with all your soul, and with all your strength, and with all your mind; and your neighbor as yourself." Second Catholic Edition Revised Stand Version

Answer 3

It would depend entirely on what you perceive as god and which religion you adhere to.
Many religions insist there is only one god, others disagree.

The majority of the human race believes in some form of religious doctrine most of which are mutually incompatible. Logic dictates that they all cannot therefore be true or correct.
Ultimately you must decide for yourself what is moral and ethical and a god is not necessary for you to make such a decision though many, if not most, religions can guide you.